<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://www.federalrealty.com/role/BusinessAndOrganization" xlink:href="frt-20170630.xsd#BusinessAndOrganization" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/BusinessAndOrganizationDetails" xlink:href="frt-20170630.xsd#BusinessAndOrganizationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/CommitmentsAndContingencies" xlink:href="frt-20170630.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/CommitmentsAndContingenciesDetails" xlink:href="frt-20170630.xsd#CommitmentsAndContingenciesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ComponentsOfRentalIncome" xlink:href="frt-20170630.xsd#ComponentsOfRentalIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ComponentsOfRentalIncomeScheduleOfMinimumRentDetails" xlink:href="frt-20170630.xsd#ComponentsOfRentalIncomeScheduleOfMinimumRentDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ComponentsOfRentalIncomeScheduleOfPrincipalComponentsOfRentalIncomeDetails" xlink:href="frt-20170630.xsd#ComponentsOfRentalIncomeScheduleOfPrincipalComponentsOfRentalIncomeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ComponentsOfRentalIncomeTables" xlink:href="frt-20170630.xsd#ComponentsOfRentalIncomeTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedBalanceSheets" xlink:href="frt-20170630.xsd#ConsolidatedBalanceSheets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedBalanceSheetsParentheticals" xlink:href="frt-20170630.xsd#ConsolidatedBalanceSheetsParentheticals" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementOfShareholdersEquity" xlink:href="frt-20170630.xsd#ConsolidatedStatementOfShareholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementOfShareholdersEquityParentheticals" xlink:href="frt-20170630.xsd#ConsolidatedStatementOfShareholdersEquityParentheticals" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementsOfCashFlows" xlink:href="frt-20170630.xsd#ConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ConsolidatedStatementsOfOperations" xlink:href="frt-20170630.xsd#ConsolidatedStatementsOfOperations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/Debt" xlink:href="frt-20170630.xsd#Debt" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/DebtDetails" xlink:href="frt-20170630.xsd#DebtDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/DocumentAndEntityInformationDocument" xlink:href="frt-20170630.xsd#DocumentAndEntityInformationDocument" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/EarningsPerShare" xlink:href="frt-20170630.xsd#EarningsPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/EarningsPerShareNarrativeDetails" xlink:href="frt-20170630.xsd#EarningsPerShareNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/EarningsPerShareScheduleOfEarningsPerShareDetails" xlink:href="frt-20170630.xsd#EarningsPerShareScheduleOfEarningsPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/EarningsPerShareTables" xlink:href="frt-20170630.xsd#EarningsPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/FairValueOfFinancialInstruments" xlink:href="frt-20170630.xsd#FairValueOfFinancialInstruments" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsDetails" xlink:href="frt-20170630.xsd#FairValueOfFinancialInstrumentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsSummaryOfCarryingValueAndFairValueOfFinancialInstrumentsDetails" xlink:href="frt-20170630.xsd#FairValueOfFinancialInstrumentsSummaryOfCarryingValueAndFairValueOfFinancialInstrumentsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsSummaryOfFinancialLiabilitiesMeasuredOnRecurringBasisDetails" xlink:href="frt-20170630.xsd#FairValueOfFinancialInstrumentsSummaryOfFinancialLiabilitiesMeasuredOnRecurringBasisDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsTables" xlink:href="frt-20170630.xsd#FairValueOfFinancialInstrumentsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/RealEstate" xlink:href="frt-20170630.xsd#RealEstate" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/RealEstateSignificantAcquisitionsAndDispositionsDetails" xlink:href="frt-20170630.xsd#RealEstateSignificantAcquisitionsAndDispositionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareBasedCompensationDetails" xlink:href="frt-20170630.xsd#ShareBasedCompensationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareBasedCompensationPlans" xlink:href="frt-20170630.xsd#ShareBasedCompensationPlans" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareBasedCompensationPlansTables" xlink:href="frt-20170630.xsd#ShareBasedCompensationPlansTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareholdersEquity" xlink:href="frt-20170630.xsd#ShareholdersEquity" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareholdersEquityNarrativeDetails" xlink:href="frt-20170630.xsd#ShareholdersEquityNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareholdersEquitySummaryOfDividendsDetails" xlink:href="frt-20170630.xsd#ShareholdersEquitySummaryOfDividendsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/ShareholdersEquityTables" xlink:href="frt-20170630.xsd#ShareholdersEquityTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPolicies" xlink:href="frt-20170630.xsd#SummaryOfSignificantAccountingPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesConsolidatedStatementOfCashFlowsSupplementalDisclosuresDetails" xlink:href="frt-20170630.xsd#SummaryOfSignificantAccountingPoliciesConsolidatedStatementOfCashFlowsSupplementalDisclosuresDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesPolicy" xlink:href="frt-20170630.xsd#SummaryOfSignificantAccountingPoliciesPolicy" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesRecentlyAdoptedAccountingPronouncementsDetails" xlink:href="frt-20170630.xsd#SummaryOfSignificantAccountingPoliciesRecentlyAdoptedAccountingPronouncementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesRevenueRecognitionDetails" xlink:href="frt-20170630.xsd#SummaryOfSignificantAccountingPoliciesRevenueRecognitionDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesTables" xlink:href="frt-20170630.xsd#SummaryOfSignificantAccountingPoliciesTables" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/BusinessAndOrganization" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/BusinessAndOrganizationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/CommitmentsAndContingenciesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncashOrPartNoncashAcquisitionsLineItems" xlink:label="loc_us-gaap_NoncashOrPartNoncashAcquisitionsLineItems_30B96F075B675AEFB9E4534A72D385EE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncashOrPartNoncashAcquisitionsTable" xlink:label="loc_us-gaap_NoncashOrPartNoncashAcquisitionsTable_B49FDCEF25BB559487034A62E432BB0B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NoncashOrPartNoncashAcquisitionsLineItems_30B96F075B675AEFB9E4534A72D385EE" xlink:to="loc_us-gaap_NoncashOrPartNoncashAcquisitionsTable_B49FDCEF25BB559487034A62E432BB0B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_8C322E502CBB563BA85C9B6591E94DA0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NoncashOrPartNoncashAcquisitionsTable_B49FDCEF25BB559487034A62E432BB0B" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_8C322E502CBB563BA85C9B6591E94DA0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_39F8CFABE1FFF467D82280BA52C5C58C_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8C322E502CBB563BA85C9B6591E94DA0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_39F8CFABE1FFF467D82280BA52C5C58C_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D3F02CBCDEEE5AFCA6B47C993D046774" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_8C322E502CBB563BA85C9B6591E94DA0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D3F02CBCDEEE5AFCA6B47C993D046774" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_SanAntonioCenterMember" xlink:label="loc_frt_SanAntonioCenterMember_DC0D5E6290E15942936B05D4A65301AC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_D3F02CBCDEEE5AFCA6B47C993D046774" xlink:to="loc_frt_SanAntonioCenterMember_DC0D5E6290E15942936B05D4A65301AC" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_PaymentstoAcquireOutstandingInterest" xlink:label="loc_frt_PaymentstoAcquireOutstandingInterest_9ED934D318E3587FB7EC1D628757A907" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashOrPartNoncashAcquisitionsLineItems_30B96F075B675AEFB9E4534A72D385EE" xlink:to="loc_frt_PaymentstoAcquireOutstandingInterest_9ED934D318E3587FB7EC1D628757A907" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_NumberofdownREITunitsissuedinconnectionwithpurchaseoption" xlink:label="loc_frt_NumberofdownREITunitsissuedinconnectionwithpurchaseoption_1CBFC233EC86560282854D60480003D0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashOrPartNoncashAcquisitionsLineItems_30B96F075B675AEFB9E4534A72D385EE" xlink:to="loc_frt_NumberofdownREITunitsissuedinconnectionwithpurchaseoption_1CBFC233EC86560282854D60480003D0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ComponentsOfRentalIncome" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ComponentsOfRentalIncomeScheduleOfMinimumRentDetails" xlink:type="extended">
    <link:loc xlink:href="frt-20170630.xsd#frt_MinimumRentLineItems" xlink:label="loc_frt_MinimumRentLineItems_ACF45A236B2754E7A265B5CE65D1C698" xlink:type="locator" />
    <link:loc xlink:href="frt-20170630.xsd#frt_ScheduleOfMinimumRentsTable" xlink:label="loc_frt_ScheduleOfMinimumRentsTable_FEC226BBC6205EB6B7232637289DD0E1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_frt_MinimumRentLineItems_ACF45A236B2754E7A265B5CE65D1C698" xlink:to="loc_frt_ScheduleOfMinimumRentsTable_FEC226BBC6205EB6B7232637289DD0E1" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_7E2095C326F05D239CF5FB4143203909" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_frt_ScheduleOfMinimumRentsTable_FEC226BBC6205EB6B7232637289DD0E1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_7E2095C326F05D239CF5FB4143203909" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A3769D5EF8FD5BE907BA80BA52B10B19_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_7E2095C326F05D239CF5FB4143203909" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A3769D5EF8FD5BE907BA80BA52B10B19_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A4A408DE9DEE5ED5B4B2610CA6019853" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_7E2095C326F05D239CF5FB4143203909" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A4A408DE9DEE5ED5B4B2610CA6019853" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AboveMarketLeasesMember" xlink:label="loc_us-gaap_AboveMarketLeasesMember_6A376C8A5A9E5570A564A28BE09E50C3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A4A408DE9DEE5ED5B4B2610CA6019853" xlink:to="loc_us-gaap_AboveMarketLeasesMember_6A376C8A5A9E5570A564A28BE09E50C3" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_BelowMarketLeaseMember" xlink:label="loc_frt_BelowMarketLeaseMember_92DC3F0204395667A45EB4CAE6E41F18" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_A4A408DE9DEE5ED5B4B2610CA6019853" xlink:to="loc_frt_BelowMarketLeaseMember_92DC3F0204395667A45EB4CAE6E41F18" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StraightLineRent" xlink:label="loc_us-gaap_StraightLineRent_DD5636FD46345489AA8854083E30741D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_MinimumRentLineItems_ACF45A236B2754E7A265B5CE65D1C698" xlink:to="loc_us-gaap_StraightLineRent_DD5636FD46345489AA8854083E30741D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfAboveAndBelowMarketLeases" xlink:label="loc_us-gaap_AmortizationOfAboveAndBelowMarketLeases_F707CD1A17125B568B60FEA6E2CA0842" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_MinimumRentLineItems_ACF45A236B2754E7A265B5CE65D1C698" xlink:to="loc_us-gaap_AmortizationOfAboveAndBelowMarketLeases_F707CD1A17125B568B60FEA6E2CA0842" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ComponentsOfRentalIncomeScheduleOfPrincipalComponentsOfRentalIncomeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_6C6D8D70E616539FB528B953157C529C" xlink:type="locator" />
    <link:loc xlink:href="frt-20170630.xsd#frt_ComponentsOfRentalIncomeTable" xlink:label="loc_frt_ComponentsOfRentalIncomeTable_98A1769AB00A5857B47904CEFBCBA94E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_6C6D8D70E616539FB528B953157C529C" xlink:to="loc_frt_ComponentsOfRentalIncomeTable_98A1769AB00A5857B47904CEFBCBA94E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_B4536CE3039B5D63B4F00FE6A2319628" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_frt_ComponentsOfRentalIncomeTable_98A1769AB00A5857B47904CEFBCBA94E" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_B4536CE3039B5D63B4F00FE6A2319628" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_4B2B41F64435FF5927D180BA52B53661_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_B4536CE3039B5D63B4F00FE6A2319628" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_4B2B41F64435FF5927D180BA52B53661_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_D0166F02F8915891A529156317A9B432" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis_B4536CE3039B5D63B4F00FE6A2319628" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_D0166F02F8915891A529156317A9B432" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommercialRealEstateMember" xlink:label="loc_us-gaap_CommercialRealEstateMember_798EB995416B5DA9A4E6AC23B398BCDA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_D0166F02F8915891A529156317A9B432" xlink:to="loc_us-gaap_CommercialRealEstateMember_798EB995416B5DA9A4E6AC23B398BCDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ResidentialRealEstateMember" xlink:label="loc_us-gaap_ResidentialRealEstateMember_7DB163D563F45F17A7E0F5A38ACC9E9A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain_D0166F02F8915891A529156317A9B432" xlink:to="loc_us-gaap_ResidentialRealEstateMember_7DB163D563F45F17A7E0F5A38ACC9E9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue" xlink:label="loc_us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue_15F10C0F8C385357A9A76BE57EB46004" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6C6D8D70E616539FB528B953157C529C" xlink:to="loc_us-gaap_OperatingLeasesIncomeStatementMinimumLeaseRevenue_15F10C0F8C385357A9A76BE57EB46004" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TenantReimbursements" xlink:label="loc_us-gaap_TenantReimbursements_47B53ACD78B454C7A86C52154E7C942A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6C6D8D70E616539FB528B953157C529C" xlink:to="loc_us-gaap_TenantReimbursements_47B53ACD78B454C7A86C52154E7C942A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PercentageRent" xlink:label="loc_us-gaap_PercentageRent_75F161DEF1C85042B45E74ACEC92A310" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6C6D8D70E616539FB528B953157C529C" xlink:to="loc_us-gaap_PercentageRent_75F161DEF1C85042B45E74ACEC92A310" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_OtherRentalIncome" xlink:label="loc_frt_OtherRentalIncome_E74E3C56358554159EF77BE06CCA8730" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6C6D8D70E616539FB528B953157C529C" xlink:to="loc_frt_OtherRentalIncome_E74E3C56358554159EF77BE06CCA8730" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesIncomeStatementLeaseRevenue" xlink:label="loc_us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_99B189BF51855E8F86CDF232EBD40F8C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6C6D8D70E616539FB528B953157C529C" xlink:to="loc_us-gaap_OperatingLeasesIncomeStatementLeaseRevenue_99B189BF51855E8F86CDF232EBD40F8C" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ComponentsOfRentalIncomeTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedBalanceSheets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedBalanceSheetsParentheticals" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementOfShareholdersEquity" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_4968DC2EA9D95B45AC44F090A4F89CA6" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_B7DD1FFFC86C510A8CB0CF13E2AF2BE3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_4968DC2EA9D95B45AC44F090A4F89CA6" xlink:to="loc_us-gaap_StatementTable_B7DD1FFFC86C510A8CB0CF13E2AF2BE3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_38B623D8AB5C55C8864E13E4292A1D78" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_B7DD1FFFC86C510A8CB0CF13E2AF2BE3" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_38B623D8AB5C55C8864E13E4292A1D78" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_24E8C0389D5A08ABE5D399EBA7029A8B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_38B623D8AB5C55C8864E13E4292A1D78" xlink:to="loc_us-gaap_EquityComponentDomain_24E8C0389D5A08ABE5D399EBA7029A8B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_38B623D8AB5C55C8864E13E4292A1D78" xlink:to="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredStockMember" xlink:label="loc_us-gaap_PreferredStockMember_1F714B88499556BC9C4322A8508BDAA5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:to="loc_us-gaap_PreferredStockMember_1F714B88499556BC9C4322A8508BDAA5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_B3412BADD10D51D196C256AD6804A1D1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:to="loc_us-gaap_CommonStockMember_B3412BADD10D51D196C256AD6804A1D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_712D60710D9058E9BD24B6CCFDB1CB2A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_712D60710D9058E9BD24B6CCFDB1CB2A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember" xlink:label="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember_C6EF8C7C60E85E9AA755586D563D6A78" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:to="loc_us-gaap_AccumulatedDistributionsInExcessOfNetIncomeMember_C6EF8C7C60E85E9AA755586D563D6A78" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_824B7D9CA1B25D66A96C8C85BFFA673C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_824B7D9CA1B25D66A96C8C85BFFA673C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncontrollingInterestMember" xlink:label="loc_us-gaap_NoncontrollingInterestMember_3ECB0F17177F5879A5C48BE85263E2BE" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_1E1615EF97895AD6B25CD4EC06607598" xlink:to="loc_us-gaap_NoncontrollingInterestMember_3ECB0F17177F5879A5C48BE85263E2BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4968DC2EA9D95B45AC44F090A4F89CA6" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="loc_us-gaap_SharesOutstanding_9B1C28D616FB5F51A1FDFE352952DE92" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_SharesOutstanding_9B1C28D616FB5F51A1FDFE352952DE92" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7CC826432E265432B93A5CF090FD8DA1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7CC826432E265432B93A5CF090FD8DA1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1" xlink:label="loc_us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1_88E6FD16D3405FA8A75FF98EA3AD2996" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1_88E6FD16D3405FA8A75FF98EA3AD2996" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_ProfitLossExcludingRedeemableNoncontrollingInterests" xlink:label="loc_frt_ProfitLossExcludingRedeemableNoncontrollingInterests_0C77690F46D952FA93D1C3FEA254C32D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_frt_ProfitLossExcludingRedeemableNoncontrollingInterests_0C77690F46D952FA93D1C3FEA254C32D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_08AB59BD68C153B9BE43B88D1577C54F" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_08AB59BD68C153B9BE43B88D1577C54F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_us-gaap_DividendsCommonStockCash_1F31676075A250E2BDBB7FC626B10CF9" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_DividendsCommonStockCash_1F31676075A250E2BDBB7FC626B10CF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsPreferredStockCash" xlink:label="loc_us-gaap_DividendsPreferredStockCash_D48BA64F6F435C698FF32E2834FD32F1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_DividendsPreferredStockCash_D48BA64F6F435C698FF32E2834FD32F1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_847B8678693F5403BB2BB2A9C2B18A04" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders_847B8678693F5403BB2BB2A9C2B18A04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_4509E70458D15DAC80AA415172349A54" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_4509E70458D15DAC80AA415172349A54" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_068409A9875B5D3CB940FA0344C7D35B" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_068409A9875B5D3CB940FA0344C7D35B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_789F848B13D6535FAEF63C23F6FC9B5E" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_789F848B13D6535FAEF63C23F6FC9B5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_30667E8F5FBA5B6889065A46F6C81AA2" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_30667E8F5FBA5B6889065A46F6C81AA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_0AE7FD39EDED5B98B2F7A2364861103F" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_0AE7FD39EDED5B98B2F7A2364861103F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_CAE297DFDDC0540C962B06A979947C60" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_CAE297DFDDC0540C962B06A979947C60" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_ShareBasedCompensationExpenseNetShares" xlink:label="loc_frt_ShareBasedCompensationExpenseNetShares_2329C1ED7C365893AEDE76713F0528CF" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_frt_ShareBasedCompensationExpenseNetShares_2329C1ED7C365893AEDE76713F0528CF" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_ShareBasedCompensationExpenseNetValue" xlink:label="loc_frt_ShareBasedCompensationExpenseNetValue_96353EEC86685D619F1A76CC2E2BB17B" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_frt_ShareBasedCompensationExpenseNetValue_96353EEC86685D619F1A76CC2E2BB17B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_FDA670E944275DA8B8F19BE23EC5F5AE" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_FDA670E944275DA8B8F19BE23EC5F5AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_F0D80413D7F4515BAA377D238EE06F22" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_F0D80413D7F4515BAA377D238EE06F22" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_ConversionAndRedemptionOfOperatingPartnershipUnitsInShares" xlink:label="loc_frt_ConversionAndRedemptionOfOperatingPartnershipUnitsInShares_33A1D72E959155048FC205C8BE2E08CB" xlink:type="locator" />
    <link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_frt_ConversionAndRedemptionOfOperatingPartnershipUnitsInShares_33A1D72E959155048FC205C8BE2E08CB" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_ConversionAndRedemptionOfOperatingPartnershipUnits" xlink:label="loc_frt_ConversionAndRedemptionOfOperatingPartnershipUnits_1FD8305C511E57288A3EC3CB5430DDB7" xlink:type="locator" />
    <link:definitionArc order="20" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_frt_ConversionAndRedemptionOfOperatingPartnershipUnits_1FD8305C511E57288A3EC3CB5430DDB7" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_Contributionsfromnoncontrollinginterests" xlink:label="loc_frt_Contributionsfromnoncontrollinginterests_998438947B5C53CAB4C031F88BF321FA" xlink:type="locator" />
    <link:definitionArc order="21" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_frt_Contributionsfromnoncontrollinginterests_998438947B5C53CAB4C031F88BF321FA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_DB45E3B21930538199B5A06177C6A1F4" xlink:type="locator" />
    <link:definitionArc order="22" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_10F66927C428522E8506D46E2CC3B3F0" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_DB45E3B21930538199B5A06177C6A1F4" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementOfShareholdersEquityParentheticals" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementsOfCashFlows" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ConsolidatedStatementsOfOperations" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/Debt" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/DebtDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_C67808A15E8056C3BA8E9933DE3F580B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_DebtInstrumentTable_C67808A15E8056C3BA8E9933DE3F580B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_96EEE8B05D9E5C37A1297D735910F6EA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C67808A15E8056C3BA8E9933DE3F580B" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_96EEE8B05D9E5C37A1297D735910F6EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_68F33DA94E8BD22E0967992CB9F510FA_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_96EEE8B05D9E5C37A1297D735910F6EA" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_68F33DA94E8BD22E0967992CB9F510FA_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_80949DF2A3815E798B046B60BCA4F66C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_96EEE8B05D9E5C37A1297D735910F6EA" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_80949DF2A3815E798B046B60BCA4F66C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MortgagesMember" xlink:label="loc_us-gaap_MortgagesMember_CF18EF63A40D5C0F965ACA251F72BE77" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_80949DF2A3815E798B046B60BCA4F66C" xlink:to="loc_us-gaap_MortgagesMember_CF18EF63A40D5C0F965ACA251F72BE77" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_01897DE016AF5DA68B708C3E943DDAAA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_80949DF2A3815E798B046B60BCA4F66C" xlink:to="loc_us-gaap_SeniorNotesMember_01897DE016AF5DA68B708C3E943DDAAA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_C5EE0D71A425574980DC0A5FBC93EA8E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C67808A15E8056C3BA8E9933DE3F580B" xlink:to="loc_us-gaap_DebtInstrumentAxis_C5EE0D71A425574980DC0A5FBC93EA8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7C89C24BA75119CAC6DC992CB9F558A4_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_C5EE0D71A425574980DC0A5FBC93EA8E" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7C89C24BA75119CAC6DC992CB9F558A4_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_EA7C4D64EC64518289D7957A9C9BE980" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_C5EE0D71A425574980DC0A5FBC93EA8E" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_EA7C4D64EC64518289D7957A9C9BE980" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_PlazaElSegundoMember" xlink:label="loc_frt_PlazaElSegundoMember_DEB18BB98E2E5A7799FB72D47838D141" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_EA7C4D64EC64518289D7957A9C9BE980" xlink:to="loc_frt_PlazaElSegundoMember_DEB18BB98E2E5A7799FB72D47838D141" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_A3.25SeniornotesMember" xlink:label="loc_frt_A3.25SeniornotesMember_5752EE8F1C7451629ABC0454AC0D848C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_EA7C4D64EC64518289D7957A9C9BE980" xlink:to="loc_frt_A3.25SeniornotesMember_5752EE8F1C7451629ABC0454AC0D848C" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_A4.50SeniornotesMember" xlink:label="loc_frt_A4.50SeniornotesMember_320E305BE98152B19522FF6170B024FA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_EA7C4D64EC64518289D7957A9C9BE980" xlink:to="loc_frt_A4.50SeniornotesMember_320E305BE98152B19522FF6170B024FA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_A4D98D56254C5B498C65D3F12877C6CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_A4D98D56254C5B498C65D3F12877C6CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RepaymentsOfLongTermDebt" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_63DAC82F40DB50668498E7F3B4214D66" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_63DAC82F40DB50668498E7F3B4214D66" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_70EEEC739B875FDE8263B5993F02BA57" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_70EEEC739B875FDE8263B5993F02BA57" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_NoteOfferingPercent" xlink:label="loc_frt_NoteOfferingPercent_62DA34B82F835561917704E34D0CD66F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_frt_NoteOfferingPercent_62DA34B82F835561917704E34D0CD66F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_87D92FA8A311554CAA98A36796108544" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_87D92FA8A311554CAA98A36796108544" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_0B173BE6938D5F739DDAC9BFA6FB99CD" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_0B173BE6938D5F739DDAC9BFA6FB99CD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_3DF67AAF26DC55AB9798D16B235AB5BE" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_3DF67AAF26DC55AB9798D16B235AB5BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_A8BD40B20E095CFDAA6808C79F156A4E" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_A8BD40B20E095CFDAA6808C79F156A4E" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_LineofcreditfacilityweightedaverageinterestratebeforeamortizationofdebtFees" xlink:label="loc_frt_LineofcreditfacilityweightedaverageinterestratebeforeamortizationofdebtFees_51A7878E26005B0C9828BEE4FA5A382A" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_frt_LineofcreditfacilityweightedaverageinterestratebeforeamortizationofdebtFees_51A7878E26005B0C9828BEE4FA5A382A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityAverageOutstandingAmount" xlink:label="loc_us-gaap_LineOfCreditFacilityAverageOutstandingAmount_17E72B49A5085E80993F1089C7DD9217" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_LineOfCreditFacilityAverageOutstandingAmount_17E72B49A5085E80993F1089C7DD9217" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaap_LineOfCredit_208A9E2B3A5F5F23AF2DA638D08C9455" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9EC0188B1B835B9A9CAC0EFAA61FDC51" xlink:to="loc_us-gaap_LineOfCredit_208A9E2B3A5F5F23AF2DA638D08C9455" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/DocumentAndEntityInformationDocument" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/EarningsPerShare" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/EarningsPerShareNarrativeDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/EarningsPerShareScheduleOfEarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_7BA743794EAB5552B747F6AEA02E7680" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2926063903395D54BDED453E083C9B17" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_7BA743794EAB5552B747F6AEA02E7680" xlink:to="loc_us-gaap_StatementTable_2926063903395D54BDED453E083C9B17" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_F18A0403275F5CE3B617FCE6189D954D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2926063903395D54BDED453E083C9B17" xlink:to="loc_us-gaap_StatementScenarioAxis_F18A0403275F5CE3B617FCE6189D954D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_1A3CC247F3E8050C931580BA52A0ED0C_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_F18A0403275F5CE3B617FCE6189D954D" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_1A3CC247F3E8050C931580BA52A0ED0C_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_13D20D4478235C37A47F2FA3E427B7A1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_F18A0403275F5CE3B617FCE6189D954D" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_13D20D4478235C37A47F2FA3E427B7A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_7BF9437F77D850F89637A4217AF8380A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2926063903395D54BDED453E083C9B17" xlink:to="loc_us-gaap_StatementClassOfStockAxis_7BF9437F77D850F89637A4217AF8380A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_ECED9131BA7F9445E41480BA52A08459_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_7BF9437F77D850F89637A4217AF8380A" xlink:to="loc_us-gaap_ClassOfStockDomain_ECED9131BA7F9445E41480BA52A08459_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_174116A992F758E5838F9188FEA60610" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_7BF9437F77D850F89637A4217AF8380A" xlink:to="loc_us-gaap_ClassOfStockDomain_174116A992F758E5838F9188FEA60610" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/EarningsPerShareTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/FairValueOfFinancialInstruments" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_AEFD9106F52655D5B19E1934282D5CD7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_AEFD9106F52655D5B19E1934282D5CD7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_B29C583DCDFC0BBD745480BA52D06E7F_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_AEFD9106F52655D5B19E1934282D5CD7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_B29C583DCDFC0BBD745480BA52D06E7F_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_11F27E9FB74E5A19BF218F120A8B8F46" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_AEFD9106F52655D5B19E1934282D5CD7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_11F27E9FB74E5A19BF218F120A8B8F46" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_0BBB6DAF33B05A4C96BDA4B65168AA56" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_11F27E9FB74E5A19BF218F120A8B8F46" xlink:to="loc_us-gaap_InterestRateSwapMember_0BBB6DAF33B05A4C96BDA4B65168AA56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_65F74A35897557C5B8EBBF753E6EF82B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_65F74A35897557C5B8EBBF753E6EF82B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_E3E9868443D0943897B280BA52D0A8C0_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_65F74A35897557C5B8EBBF753E6EF82B" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_E3E9868443D0943897B280BA52D0A8C0_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_3A24174EE90F554F8AEA4335D330E79B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_65F74A35897557C5B8EBBF753E6EF82B" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_3A24174EE90F554F8AEA4335D330E79B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_46E4A4774CF25E67B3E98C4BC68A7B0C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_3A24174EE90F554F8AEA4335D330E79B" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_46E4A4774CF25E67B3E98C4BC68A7B0C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_A25797808CF65471A162D6451F87A6CF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:to="loc_us-gaap_DebtInstrumentAxis_A25797808CF65471A162D6451F87A6CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_DF7635D9C6995317F02F80BA52D095A1_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_A25797808CF65471A162D6451F87A6CF" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_DF7635D9C6995317F02F80BA52D095A1_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_DC1433DA678C5D6F87A9A46036740A0A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_A25797808CF65471A162D6451F87A6CF" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_DC1433DA678C5D6F87A9A46036740A0A" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_TermLoanMember" xlink:label="loc_frt_TermLoanMember_6533D1D727275A7B98400892C789CC89" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_DC1433DA678C5D6F87A9A46036740A0A" xlink:to="loc_frt_TermLoanMember_6533D1D727275A7B98400892C789CC89" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_C9688D5CE4305552A672144281571900" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_C9688D5CE4305552A672144281571900" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_271B02873554947B3E5080BA52D00115_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_C9688D5CE4305552A672144281571900" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_271B02873554947B3E5080BA52D00115_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_70E33060A66351E88946A37A07EDBD04" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_C9688D5CE4305552A672144281571900" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_70E33060A66351E88946A37A07EDBD04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesMember" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_2A9AD568D40B587F8334F9A3901DF354" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_70E33060A66351E88946A37A07EDBD04" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_2A9AD568D40B587F8334F9A3901DF354" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C2CBB34C718F50648314AB2BAA505A8B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C2CBB34C718F50648314AB2BAA505A8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_89E49AFFC7AAF885FF8080BA52D16214_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C2CBB34C718F50648314AB2BAA505A8B" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_89E49AFFC7AAF885FF8080BA52D16214_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_F1B6111A1B73501C893AD32ECCB0243D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_C2CBB34C718F50648314AB2BAA505A8B" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_F1B6111A1B73501C893AD32ECCB0243D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_2FC10FE849D3538C862BB475B742EED6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_F1B6111A1B73501C893AD32ECCB0243D" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_2FC10FE849D3538C862BB475B742EED6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_5878CB39468F5CEFB52093B52708C18F" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_D04D0E7036D7511D92ED911AAED48B03" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_5878CB39468F5CEFB52093B52708C18F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_F5C13C5411799366684480BA52D1A319_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_5878CB39468F5CEFB52093B52708C18F" xlink:to="loc_us-gaap_EquityComponentDomain_F5C13C5411799366684480BA52D1A319_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_5658E9A074605810AA8022911B45A40A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_5878CB39468F5CEFB52093B52708C18F" xlink:to="loc_us-gaap_EquityComponentDomain_5658E9A074605810AA8022911B45A40A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_4B379CA35B925C6EAFD97DD6BFCA7B3F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5658E9A074605810AA8022911B45A40A" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_4B379CA35B925C6EAFD97DD6BFCA7B3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfInterestRateDerivativesHeld" xlink:label="loc_us-gaap_NumberOfInterestRateDerivativesHeld_168F6CD1B11E591F92269FB3CD44B4A9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_NumberOfInterestRateDerivativesHeld_168F6CD1B11E591F92269FB3CD44B4A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeLiabilityNotionalAmount" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_224A8229F54F55A2A9F486A6E6C3FA01" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_224A8229F54F55A2A9F486A6E6C3FA01" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherNotesPayable" xlink:label="loc_us-gaap_OtherNotesPayable_C4186AD4AD2154E282036FB1FEFB2382" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_OtherNotesPayable_C4186AD4AD2154E282036FB1FEFB2382" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeFixedInterestRate" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_F93F3F73076B551382A2FE6EF091DBED" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_F93F3F73076B551382A2FE6EF091DBED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_6679B63D5D2959329B3058C97ECA82CE" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_6679B63D5D2959329B3058C97ECA82CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_9C441E4295B65DE7A8AEE808C14650AF" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_DerivativeLiabilities_9C441E4295B65DE7A8AEE808C14650AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_5D3FEE30B9A959FCBE3D243E1777FD5B" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_5D3FEE30B9A959FCBE3D243E1777FD5B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_F15F0EDBD1335B12A15DE8886097D4DB" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_A449CC6701E85A5A834F97B0E2B4AFD0" xlink:to="loc_us-gaap_InterestRateCashFlowHedgeGainLossReclassifiedToEarningsNet_F15F0EDBD1335B12A15DE8886097D4DB" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsSummaryOfCarryingValueAndFairValueOfFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_1BC61C99FE1651BCAA3D90D55F86D8BB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTable" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_01C64C8B087C540F88B23EC702035F1A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_1BC61C99FE1651BCAA3D90D55F86D8BB" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_01C64C8B087C540F88B23EC702035F1A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_41E8BB4FFF755337B61A61C75EB52F1E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_01C64C8B087C540F88B23EC702035F1A" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_41E8BB4FFF755337B61A61C75EB52F1E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_9195C3C3980EF4FAE63B80BA52D5475E_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_41E8BB4FFF755337B61A61C75EB52F1E" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_9195C3C3980EF4FAE63B80BA52D5475E_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_2B54B97425115EACB9F6AD9433E50E62" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_41E8BB4FFF755337B61A61C75EB52F1E" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_2B54B97425115EACB9F6AD9433E50E62" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_MortgagesPayableAndNotesPayableMember" xlink:label="loc_frt_MortgagesPayableAndNotesPayableMember_29F2B75ADE6358B094743FA32142BBAE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_2B54B97425115EACB9F6AD9433E50E62" xlink:to="loc_frt_MortgagesPayableAndNotesPayableMember_29F2B75ADE6358B094743FA32142BBAE" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_SeniorNotesAndDebenturesMember" xlink:label="loc_frt_SeniorNotesAndDebenturesMember_F3816B474E955747A58752C124B76747" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_2B54B97425115EACB9F6AD9433E50E62" xlink:to="loc_frt_SeniorNotesAndDebenturesMember_F3816B474E955747A58752C124B76747" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_F0F6745A0DEF5E3F861CBB95AEB644C3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_01C64C8B087C540F88B23EC702035F1A" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_F0F6745A0DEF5E3F861CBB95AEB644C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_FCEE08EFA53A03E9E0F280BA52D6A132_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_F0F6745A0DEF5E3F861CBB95AEB644C3" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_FCEE08EFA53A03E9E0F280BA52D6A132_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_E6B18C1094D05AE0BFB71889D552B2B0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_F0F6745A0DEF5E3F861CBB95AEB644C3" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_E6B18C1094D05AE0BFB71889D552B2B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_E1ABED5E811F52A1828C737E6D3B4A2E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_E6B18C1094D05AE0BFB71889D552B2B0" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_E1ABED5E811F52A1828C737E6D3B4A2E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_CD49B9FCA3A5544EA6A70FD2BB250EB2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_E1ABED5E811F52A1828C737E6D3B4A2E" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_CD49B9FCA3A5544EA6A70FD2BB250EB2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_1D428F99B6D4523C8B0872D8F289B1B2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_E1ABED5E811F52A1828C737E6D3B4A2E" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_1D428F99B6D4523C8B0872D8F289B1B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtFairValue" xlink:label="loc_us-gaap_LongTermDebtFairValue_64FA712A76DA58A0A77DA12C6278087B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_1BC61C99FE1651BCAA3D90D55F86D8BB" xlink:to="loc_us-gaap_LongTermDebtFairValue_64FA712A76DA58A0A77DA12C6278087B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsSummaryOfFinancialLiabilitiesMeasuredOnRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_94FB21154C0A597098B9F329CE53383E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_7419C4E48E4A5F7E9958D268EF448BD3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_94FB21154C0A597098B9F329CE53383E" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_7419C4E48E4A5F7E9958D268EF448BD3" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_155AA5F4CCC2503A86AD4141D6102278" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_7419C4E48E4A5F7E9958D268EF448BD3" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_155AA5F4CCC2503A86AD4141D6102278" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_2F73DD2912708FA17CE980BA52CA893B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_155AA5F4CCC2503A86AD4141D6102278" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_2F73DD2912708FA17CE980BA52CA893B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_54F04BD4F22E560DA2C62E890D50BC90" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_155AA5F4CCC2503A86AD4141D6102278" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_54F04BD4F22E560DA2C62E890D50BC90" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_8D52D86B9A2B55DBB896DD951AA6BA62" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_54F04BD4F22E560DA2C62E890D50BC90" xlink:to="loc_us-gaap_InterestRateSwapMember_8D52D86B9A2B55DBB896DD951AA6BA62" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_255C06627E0F51D0BE88107575EE8E06" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_7419C4E48E4A5F7E9958D268EF448BD3" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_255C06627E0F51D0BE88107575EE8E06" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_81B81CFE599B9B4C03AE80BA52CB681B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_255C06627E0F51D0BE88107575EE8E06" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_81B81CFE599B9B4C03AE80BA52CB681B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_2013250CFB615193A347EC06350E5FA8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_255C06627E0F51D0BE88107575EE8E06" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_2013250CFB615193A347EC06350E5FA8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_93C4942E217358898C3AD0508D33F179" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_2013250CFB615193A347EC06350E5FA8" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_93C4942E217358898C3AD0508D33F179" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02C201BA1B305B44977CC3F4052C90FD" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_7419C4E48E4A5F7E9958D268EF448BD3" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02C201BA1B305B44977CC3F4052C90FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_D7FD54CA84F6097A38DD80BA52CB5669_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02C201BA1B305B44977CC3F4052C90FD" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_D7FD54CA84F6097A38DD80BA52CB5669_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0DF3FDA029635B94B48916FFBAC04350" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_02C201BA1B305B44977CC3F4052C90FD" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0DF3FDA029635B94B48916FFBAC04350" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_19C0696755A95FE38EC7C53E4D778897" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0DF3FDA029635B94B48916FFBAC04350" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_19C0696755A95FE38EC7C53E4D778897" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_5A6AA19C66115545AF0351D9218DD83A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0DF3FDA029635B94B48916FFBAC04350" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_5A6AA19C66115545AF0351D9218DD83A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_A57D49B6B2F050AD84CC14EFCF775637" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0DF3FDA029635B94B48916FFBAC04350" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_A57D49B6B2F050AD84CC14EFCF775637" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_99A72CB87C765361A55B1B3EE530C685" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_94FB21154C0A597098B9F329CE53383E" xlink:to="loc_us-gaap_DerivativeLiabilities_99A72CB87C765361A55B1B3EE530C685" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/FairValueOfFinancialInstrumentsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/RealEstate" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/RealEstateSignificantAcquisitionsAndDispositionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1BB51DF5A758583EA77F077C621ECEFD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1BB51DF5A758583EA77F077C621ECEFD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_0791BDE99607546A8AE4CD0CA398B65A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1BB51DF5A758583EA77F077C621ECEFD" xlink:to="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_0791BDE99607546A8AE4CD0CA398B65A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_1B304B220C8A4E6A1B2999517381DF2B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_0791BDE99607546A8AE4CD0CA398B65A" xlink:to="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_1B304B220C8A4E6A1B2999517381DF2B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_408437C642BD5E1AA143CFDB94E99951" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_0791BDE99607546A8AE4CD0CA398B65A" xlink:to="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_408437C642BD5E1AA143CFDB94E99951" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_HastingsRanchPlazaMember" xlink:label="loc_frt_HastingsRanchPlazaMember_9F902B5D1A935F3C9E8EAC7795C85039" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_408437C642BD5E1AA143CFDB94E99951" xlink:to="loc_frt_HastingsRanchPlazaMember_9F902B5D1A935F3C9E8EAC7795C85039" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_RiverpointCenterMember" xlink:label="loc_frt_RiverpointCenterMember_2340B3E81AFE5E0B8778F9D0769E3979" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_408437C642BD5E1AA143CFDB94E99951" xlink:to="loc_frt_RiverpointCenterMember_2340B3E81AFE5E0B8778F9D0769E3979" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_AssemblySquareMarketPlaceAssemblyRowMember" xlink:label="loc_frt_AssemblySquareMarketPlaceAssemblyRowMember_FA24C3968F8857FEAF3C9AB3CFC1E32F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_408437C642BD5E1AA143CFDB94E99951" xlink:to="loc_frt_AssemblySquareMarketPlaceAssemblyRowMember_FA24C3968F8857FEAF3C9AB3CFC1E32F" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_A170017304thStreetMember" xlink:label="loc_frt_A170017304thStreetMember_BFE7AB1D365352D3906E792F6C07281D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_408437C642BD5E1AA143CFDB94E99951" xlink:to="loc_frt_A170017304thStreetMember_BFE7AB1D365352D3906E792F6C07281D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_D8E7EDDAA5EC565A8050041DCEA1A990" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1BB51DF5A758583EA77F077C621ECEFD" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_D8E7EDDAA5EC565A8050041DCEA1A990" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_66D70ACB039186C15181995173818EEB_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_D8E7EDDAA5EC565A8050041DCEA1A990" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_66D70ACB039186C15181995173818EEB_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_BDC2853C6F925154B170AC1153D6A2B2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_D8E7EDDAA5EC565A8050041DCEA1A990" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_BDC2853C6F925154B170AC1153D6A2B2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsMember" xlink:label="loc_us-gaap_OtherAssetsMember_6821C91C87205203AFA0519199A9CB4A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_BDC2853C6F925154B170AC1153D6A2B2" xlink:to="loc_us-gaap_OtherAssetsMember_6821C91C87205203AFA0519199A9CB4A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherLiabilitiesMember" xlink:label="loc_us-gaap_OtherLiabilitiesMember_A3A670BC03E55F2D8A57348A95F5C2B3" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_BDC2853C6F925154B170AC1153D6A2B2" xlink:to="loc_us-gaap_OtherLiabilitiesMember_A3A670BC03E55F2D8A57348A95F5C2B3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52D0F9A4212252D99A2B3D49A611DB15" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1BB51DF5A758583EA77F077C621ECEFD" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52D0F9A4212252D99A2B3D49A611DB15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_37FC7F78DC579473C6C599517382B95B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52D0F9A4212252D99A2B3D49A611DB15" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_37FC7F78DC579473C6C599517382B95B_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_D9BA2720E2AD5F18B5F9CDAD1C003675" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_52D0F9A4212252D99A2B3D49A611DB15" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_D9BA2720E2AD5F18B5F9CDAD1C003675" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LeasesAcquiredInPlaceMember" xlink:label="loc_us-gaap_LeasesAcquiredInPlaceMember_081B476713F25316949E6B89CA3EBEA6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_D9BA2720E2AD5F18B5F9CDAD1C003675" xlink:to="loc_us-gaap_LeasesAcquiredInPlaceMember_081B476713F25316949E6B89CA3EBEA6" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_LeaseliabilitiesMember" xlink:label="loc_frt_LeaseliabilitiesMember_384FBE36611C5145BD383C90F78125E4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_D9BA2720E2AD5F18B5F9CDAD1C003675" xlink:to="loc_frt_LeaseliabilitiesMember_384FBE36611C5145BD383C90F78125E4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AboveMarketLeasesMember" xlink:label="loc_us-gaap_AboveMarketLeasesMember_948905B6319E5789B72EAAF117DE5460" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_D9BA2720E2AD5F18B5F9CDAD1C003675" xlink:to="loc_us-gaap_AboveMarketLeasesMember_948905B6319E5789B72EAAF117DE5460" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7D43F95A9BA354C687BA46968D7BBEEB" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_1BB51DF5A758583EA77F077C621ECEFD" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7D43F95A9BA354C687BA46968D7BBEEB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_B0085E82E7D59DBD1970995173824FE3_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7D43F95A9BA354C687BA46968D7BBEEB" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_B0085E82E7D59DBD1970995173824FE3_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC7F16FF2C46529EA18BCBDE469D4AC3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_7D43F95A9BA354C687BA46968D7BBEEB" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC7F16FF2C46529EA18BCBDE469D4AC3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LandMember" xlink:label="loc_us-gaap_LandMember_1BF8D88463BC504190C361C27BD5960A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC7F16FF2C46529EA18BCBDE469D4AC3" xlink:to="loc_us-gaap_LandMember_1BF8D88463BC504190C361C27BD5960A" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_CondominiumsMember" xlink:label="loc_frt_CondominiumsMember_EB98A9AEC33A533BB3759674849C0BBE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_FC7F16FF2C46529EA18BCBDE469D4AC3" xlink:to="loc_frt_CondominiumsMember_EB98A9AEC33A533BB3759674849C0BBE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AreaOfRealEstateProperty" xlink:label="loc_us-gaap_AreaOfRealEstateProperty_9FDDD67DC10B50C9A2DF310EAEFB16B2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_AreaOfRealEstateProperty_9FDDD67DC10B50C9A2DF310EAEFB16B2" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_Purchasepriceofrealestateacquisition" xlink:label="loc_frt_Purchasepriceofrealestateacquisition_9C45578FC9C75635B1796740248FC6CF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_frt_Purchasepriceofrealestateacquisition_9C45578FC9C75635B1796740248FC6CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1" xlink:label="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_CE43AC0387655989B6E95DAADC342FEE" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_FinitelivedIntangibleAssetsAcquired1_CE43AC0387655989B6E95DAADC342FEE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BelowMarketLeaseAcquired" xlink:label="loc_us-gaap_BelowMarketLeaseAcquired_932898EBF1F05515A3E2DAFA5CF67DE5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_BelowMarketLeaseAcquired_932898EBF1F05515A3E2DAFA5CF67DE5" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_NumberOfMembersWithPurchaseOptions" xlink:label="loc_frt_NumberOfMembersWithPurchaseOptions_0CE570C0BECB58F0A3966F8720C06917" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_frt_NumberOfMembersWithPurchaseOptions_0CE570C0BECB58F0A3966F8720C06917" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesOfRealEstate" xlink:label="loc_us-gaap_SalesOfRealEstate_64DB9E16DD0759A4A4D2F6C7BB69C448" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_SalesOfRealEstate_64DB9E16DD0759A4A4D2F6C7BB69C448" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnSaleOfPropertiesNetOfApplicableIncomeTaxes" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertiesNetOfApplicableIncomeTaxes_FD8CA394219D59558C96EFF87D6DEE84" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertiesNetOfApplicableIncomeTaxes_FD8CA394219D59558C96EFF87D6DEE84" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_Realestateacquisitiongrossvalue" xlink:label="loc_frt_Realestateacquisitiongrossvalue_81B352A509F45C33B58D3BE2D88F85CE" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_frt_Realestateacquisitiongrossvalue_81B352A509F45C33B58D3BE2D88F85CE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VariableInterestEntityOwnershipPercentage" xlink:label="loc_us-gaap_VariableInterestEntityOwnershipPercentage_E03ABB9CFC005146B944F99F9FE6C951" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_VariableInterestEntityOwnershipPercentage_E03ABB9CFC005146B944F99F9FE6C951" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnSaleOfPropertiesApplicableIncomeTaxes" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertiesApplicableIncomeTaxes_EFAC30A4EE0358C8A6E29ED008908AAF" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertiesApplicableIncomeTaxes_EFAC30A4EE0358C8A6E29ED008908AAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncontrollingInterestInVariableInterestEntity" xlink:label="loc_us-gaap_NoncontrollingInterestInVariableInterestEntity_DCE800849D16559CB25EE888D05DDE1C" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_NoncontrollingInterestInVariableInterestEntity_DCE800849D16559CB25EE888D05DDE1C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_2FF231BFC8795DDF988E67550D6B19FC" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_dei_DocumentPeriodEndDate_2FF231BFC8795DDF988E67550D6B19FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsReceivableGross" xlink:label="loc_us-gaap_AccountsReceivableGross_E208FAE5421E539FAC590BECA9339657" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_21650810EEFC56069921551EED55A951" xlink:to="loc_us-gaap_AccountsReceivableGross_E208FAE5421E539FAC590BECA9339657" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareBasedCompensationDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareBasedCompensationPlans" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareBasedCompensationPlansTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareholdersEquity" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareholdersEquityNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_A5E5CE63F83457CEA39974E50E63BF33" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_A5E5CE63F83457CEA39974E50E63BF33" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_098B6E51CED75DD88662657D1932C105" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_A5E5CE63F83457CEA39974E50E63BF33" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_098B6E51CED75DD88662657D1932C105" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_E4C71BFCF1CE95BC345798FFE1E12D85_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_098B6E51CED75DD88662657D1932C105" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_E4C71BFCF1CE95BC345798FFE1E12D85_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_AD9390CB99A15395BEADD900DB623197" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_098B6E51CED75DD88662657D1932C105" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_AD9390CB99A15395BEADD900DB623197" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_AtMarketEquityProgramMember" xlink:label="loc_frt_AtMarketEquityProgramMember_B3F734A9E2525620BB95C624D24F020A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_AD9390CB99A15395BEADD900DB623197" xlink:to="loc_frt_AtMarketEquityProgramMember_B3F734A9E2525620BB95C624D24F020A" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_StockIssuanceCostsByTypeAxis" xlink:label="loc_frt_StockIssuanceCostsByTypeAxis_17841DA661045DAE8EC0C307D81DE059" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_A5E5CE63F83457CEA39974E50E63BF33" xlink:to="loc_frt_StockIssuanceCostsByTypeAxis_17841DA661045DAE8EC0C307D81DE059" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_StockIssuanceCostsByTypeDomain" xlink:label="loc_frt_StockIssuanceCostsByTypeDomain_8D1EC8086242F4E6EBF698FFE1E2D926_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_frt_StockIssuanceCostsByTypeAxis_17841DA661045DAE8EC0C307D81DE059" xlink:to="loc_frt_StockIssuanceCostsByTypeDomain_8D1EC8086242F4E6EBF698FFE1E2D926_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_StockIssuanceCostsByTypeDomain" xlink:label="loc_frt_StockIssuanceCostsByTypeDomain_B25583C88C8753F89EBF8DD84DB167E4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_frt_StockIssuanceCostsByTypeAxis_17841DA661045DAE8EC0C307D81DE059" xlink:to="loc_frt_StockIssuanceCostsByTypeDomain_B25583C88C8753F89EBF8DD84DB167E4" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_CommissionsMember" xlink:label="loc_frt_CommissionsMember_97C84911331A5B0183B086823258E11A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_StockIssuanceCostsByTypeDomain_B25583C88C8753F89EBF8DD84DB167E4" xlink:to="loc_frt_CommissionsMember_97C84911331A5B0183B086823258E11A" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_OtherOfferingCostsMember" xlink:label="loc_frt_OtherOfferingCostsMember_C8531BF2758551488A94AA0605A41676" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_frt_StockIssuanceCostsByTypeDomain_B25583C88C8753F89EBF8DD84DB167E4" xlink:to="loc_frt_OtherOfferingCostsMember_C8531BF2758551488A94AA0605A41676" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_AggregateOfferingPriceOfCommonShare" xlink:label="loc_frt_AggregateOfferingPriceOfCommonShare_82C34B22C2285A32AC46EC5CB198DF94" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:to="loc_frt_AggregateOfferingPriceOfCommonShare_82C34B22C2285A32AC46EC5CB198DF94" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_CCDA586000DB589999E8B21E38A40CDE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_CCDA586000DB589999E8B21E38A40CDE" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_WeightedAveragePricePerCommonShare" xlink:label="loc_frt_WeightedAveragePricePerCommonShare_1A2F30F987795799960278FD36981246" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:to="loc_frt_WeightedAveragePricePerCommonShare_1A2F30F987795799960278FD36981246" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_E38FC007D8DB599593A07F6BA5001272" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_E38FC007D8DB599593A07F6BA5001272" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_54FD083D6690518AAC14119C34326FB8" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_54FD083D6690518AAC14119C34326FB8" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_RemainingCapacityToIssue" xlink:label="loc_frt_RemainingCapacityToIssue_0562E5F460D058358A242984D313446B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_782BB3B2DC3C518F9D08299B934AF7F9" xlink:to="loc_frt_RemainingCapacityToIssue_0562E5F460D058358A242984D313446B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareholdersEquitySummaryOfDividendsDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/ShareholdersEquityTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPolicies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesConsolidatedStatementOfCashFlowsSupplementalDisclosuresDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesPolicy" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesRecentlyAdoptedAccountingPronouncementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_219D5AF085A5547FB28037D0274CFBCB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_A6443712AEB45B02968B3F5A3993F0CA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_219D5AF085A5547FB28037D0274CFBCB" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_A6443712AEB45B02968B3F5A3993F0CA" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_16C3880891165D21A74931F33B8544D1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_A6443712AEB45B02968B3F5A3993F0CA" xlink:to="loc_us-gaap_RangeAxis_16C3880891165D21A74931F33B8544D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_C0CA1F0C9E10F6CEB1C280BA52F0662E_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_16C3880891165D21A74931F33B8544D1" xlink:to="loc_us-gaap_RangeMember_C0CA1F0C9E10F6CEB1C280BA52F0662E_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_49965AF8DA805D3BBAEC377C554FEAD4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_16C3880891165D21A74931F33B8544D1" xlink:to="loc_us-gaap_RangeMember_49965AF8DA805D3BBAEC377C554FEAD4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_28BCAD79783055CE8A1EE218370E2E08" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_49965AF8DA805D3BBAEC377C554FEAD4" xlink:to="loc_us-gaap_MinimumMember_28BCAD79783055CE8A1EE218370E2E08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_AB91B8B17BCE5408B7B415EC6984B2A4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_49965AF8DA805D3BBAEC377C554FEAD4" xlink:to="loc_us-gaap_MaximumMember_AB91B8B17BCE5408B7B415EC6984B2A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1" xlink:label="loc_us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1_8A299924FF05577BBE78D88DE1A2C9EF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_219D5AF085A5547FB28037D0274CFBCB" xlink:to="loc_us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1_8A299924FF05577BBE78D88DE1A2C9EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_74CA2682CA785679BB506122EB8706BA" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_219D5AF085A5547FB28037D0274CFBCB" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_74CA2682CA785679BB506122EB8706BA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_A9D8A210C85F574D9B9F90EE138E0059" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_219D5AF085A5547FB28037D0274CFBCB" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_A9D8A210C85F574D9B9F90EE138E0059" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesRevenueRecognitionDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB4A7E7AFE1654B59674F8FF0D198C76" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95F67AABA9355ED497BD6A034B720DB2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB4A7E7AFE1654B59674F8FF0D198C76" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95F67AABA9355ED497BD6A034B720DB2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98459B53DEED563489E15C3C0AF6804D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95F67AABA9355ED497BD6A034B720DB2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98459B53DEED563489E15C3C0AF6804D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_790F14C4DEB5CA120DA698FF76F6EFA7_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98459B53DEED563489E15C3C0AF6804D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_790F14C4DEB5CA120DA698FF76F6EFA7_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C5951FE246A45B239702AEF4F44482A9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_98459B53DEED563489E15C3C0AF6804D" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C5951FE246A45B239702AEF4F44482A9" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_CondominiumsMember" xlink:label="loc_frt_CondominiumsMember_8035ECD696615E3EA5BCBF87A65413D8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_C5951FE246A45B239702AEF4F44482A9" xlink:to="loc_frt_CondominiumsMember_8035ECD696615E3EA5BCBF87A65413D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_89E11F14D670515E9179E353308D2B75" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_95F67AABA9355ED497BD6A034B720DB2" xlink:to="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_89E11F14D670515E9179E353308D2B75" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_708A082517958211D36C98FEFDFB8B7A_CCC6F34E8829524EA19E3668B631AE34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_89E11F14D670515E9179E353308D2B75" xlink:to="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_708A082517958211D36C98FEFDFB8B7A_CCC6F34E8829524EA19E3668B631AE34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain" xlink:label="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_36C18DA01ED053F19530F9B0ECAA478E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis_89E11F14D670515E9179E353308D2B75" xlink:to="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_36C18DA01ED053F19530F9B0ECAA478E" xlink:type="arc" />
    <link:loc xlink:href="frt-20170630.xsd#frt_AssemblyRowandPikeRoseMember" xlink:label="loc_frt_AssemblyRowandPikeRoseMember_89714CFDBF425E6AA4CEE3611D1810C7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RealEstateAndAccumulatedDepreciationNameOfPropertyDomain_36C18DA01ED053F19530F9B0ECAA478E" xlink:to="loc_frt_AssemblyRowandPikeRoseMember_89714CFDBF425E6AA4CEE3611D1810C7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfUnitsInRealEstateProperty" xlink:label="loc_us-gaap_NumberOfUnitsInRealEstateProperty_EE813BACF8BF568CABBC457DFE716ECC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_FB4A7E7AFE1654B59674F8FF0D198C76" xlink:to="loc_us-gaap_NumberOfUnitsInRealEstateProperty_EE813BACF8BF568CABBC457DFE716ECC" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.federalrealty.com/role/SummaryOfSignificantAccountingPoliciesTables" xlink:type="extended" />
</link:linkbase>
