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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongLivedAssetsHeldForSaleNameDomain" xlink:label="LongLivedAssetsHeldForSaleNameDomain_2" xlink:title="LongLivedAssetsHeldForSaleNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="LongLivedAssetsHeldForSaleByAssetTypeAxis" xlink:to="LongLivedAssetsHeldForSaleNameDomain_2" xlink:title="definition: LongLivedAssetsHeldForSaleByAssetTypeAxis to LongLivedAssetsHeldForSaleNameDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_MYSanlorenzoMember" xlink:label="MYSanlorenzoMember" xlink:title="MYSanlorenzoMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LongLivedAssetsHeldForSaleNameDomain" xlink:to="MYSanlorenzoMember" xlink:title="definition: LongLivedAssetsHeldForSaleNameDomain to MYSanlorenzoMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="SubsequentEventTypeAxis" xlink:title="definition: ScheduleOfRelatedPartyTransactionsByRelatedPartyTable to SubsequentEventTypeAxis" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain_2" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain_2" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember" xlink:label="SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventTypeDomain" xlink:to="SubsequentEventMember" xlink:title="definition: SubsequentEventTypeDomain to SubsequentEventMember" order="1.0" />
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  <link:definitionLink xlink:type="extended" xlink:role="http://topships.org/role/LeasesLeaseArrangementsAsLesseeDetails">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems" xlink:label="LesseeLeaseDescriptionLineItems" xlink:title="LesseeLeaseDescriptionLineItems" />
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    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="LesseeOperatingLeaseDescriptionAbstract" xlink:title="definition: LesseeLeaseDescriptionLineItems to LesseeOperatingLeaseDescriptionAbstract" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseTermOfContract" xlink:label="LesseeOperatingLeaseTermOfContract" xlink:title="LesseeOperatingLeaseTermOfContract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="LesseeOperatingLeaseTermOfContract" xlink:title="definition: LesseeLeaseDescriptionLineItems to LesseeOperatingLeaseTermOfContract" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_LesseeOperatingLeaseLiabilityPerDayYearsOneAndTwo" xlink:label="LesseeOperatingLeaseLiabilityPerDayYearsOneAndTwo" xlink:title="LesseeOperatingLeaseLiabilityPerDayYearsOneAndTwo" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="LesseeOperatingLeaseLiabilityPerDayYearsOneAndTwo" xlink:title="definition: LesseeLeaseDescriptionLineItems to LesseeOperatingLeaseLiabilityPerDayYearsOneAndTwo" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_LesseeOperatingLeaseLiabilityPerDayYearsThreeAndFour" xlink:label="LesseeOperatingLeaseLiabilityPerDayYearsThreeAndFour" xlink:title="LesseeOperatingLeaseLiabilityPerDayYearsThreeAndFour" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="LesseeOperatingLeaseLiabilityPerDayYearsThreeAndFour" xlink:title="definition: LesseeLeaseDescriptionLineItems to LesseeOperatingLeaseLiabilityPerDayYearsThreeAndFour" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_LesseeOperatingLeaseLiabilityPerDayYearFive" xlink:label="LesseeOperatingLeaseLiabilityPerDayYearFive" xlink:title="LesseeOperatingLeaseLiabilityPerDayYearFive" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="LesseeOperatingLeaseLiabilityPerDayYearFive" xlink:title="definition: LesseeLeaseDescriptionLineItems to LesseeOperatingLeaseLiabilityPerDayYearFive" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_MinimumPercentageOfVotingRights" xlink:label="MinimumPercentageOfVotingRights" xlink:title="MinimumPercentageOfVotingRights" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="MinimumPercentageOfVotingRights" xlink:title="definition: LesseeLeaseDescriptionLineItems to MinimumPercentageOfVotingRights" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_SaleLeasebackTransactionMinimumLiquidityRequirement" xlink:label="SaleLeasebackTransactionMinimumLiquidityRequirement" xlink:title="SaleLeasebackTransactionMinimumLiquidityRequirement" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="SaleLeasebackTransactionMinimumLiquidityRequirement" xlink:title="definition: LesseeLeaseDescriptionLineItems to SaleLeasebackTransactionMinimumLiquidityRequirement" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset" xlink:label="OperatingLeaseRightOfUseAsset" xlink:title="OperatingLeaseRightOfUseAsset" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="OperatingLeaseRightOfUseAsset" xlink:title="definition: LesseeLeaseDescriptionLineItems to OperatingLeaseRightOfUseAsset" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiability" xlink:label="OperatingLeaseLiability" xlink:title="OperatingLeaseLiability" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="OperatingLeaseLiability" xlink:title="definition: LesseeLeaseDescriptionLineItems to OperatingLeaseLiability" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_OperatingLeaseLesseeInitialDirectCost" xlink:label="OperatingLeaseLesseeInitialDirectCost" xlink:title="OperatingLeaseLesseeInitialDirectCost" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="OperatingLeaseLesseeInitialDirectCost" xlink:title="definition: LesseeLeaseDescriptionLineItems to OperatingLeaseLesseeInitialDirectCost" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleAndLeasebackTransactionGainLossNet" xlink:label="SaleAndLeasebackTransactionGainLossNet" xlink:title="SaleAndLeasebackTransactionGainLossNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="SaleAndLeasebackTransactionGainLossNet" xlink:title="definition: LesseeLeaseDescriptionLineItems to SaleAndLeasebackTransactionGainLossNet" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseDiscountRate" xlink:label="LesseeOperatingLeaseDiscountRate" xlink:title="LesseeOperatingLeaseDiscountRate" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="LesseeOperatingLeaseDiscountRate" xlink:title="definition: LesseeLeaseDescriptionLineItems to LesseeOperatingLeaseDiscountRate" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_NumberOfVesselsSold" xlink:label="NumberOfVesselsSold" xlink:title="NumberOfVesselsSold" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="NumberOfVesselsSold" xlink:title="definition: LesseeLeaseDescriptionLineItems to NumberOfVesselsSold" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeasePayments" xlink:label="OperatingLeasePayments" xlink:title="OperatingLeasePayments" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="OperatingLeasePayments" xlink:title="definition: LesseeLeaseDescriptionLineItems to OperatingLeasePayments" order="14.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLeaseIncome" xlink:label="OperatingLeaseLeaseIncome" xlink:title="OperatingLeaseLeaseIncome" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="OperatingLeaseLeaseIncome" xlink:title="definition: LesseeLeaseDescriptionLineItems to OperatingLeaseLeaseIncome" order="15.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepositsAssetsCurrent" xlink:label="DepositsAssetsCurrent" xlink:title="DepositsAssetsCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LesseeLeaseDescriptionLineItems" xlink:to="DepositsAssetsCurrent" xlink:title="definition: LesseeLeaseDescriptionLineItems to DepositsAssetsCurrent" order="16.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable" xlink:label="LesseeLeaseDescriptionTable" xlink:title="LesseeLeaseDescriptionTable" />
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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionDescriptionAxis" xlink:label="SaleLeasebackTransactionDescriptionAxis" xlink:title="SaleLeasebackTransactionDescriptionAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="LesseeLeaseDescriptionTable" xlink:to="SaleLeasebackTransactionDescriptionAxis" xlink:title="definition: LesseeLeaseDescriptionTable to SaleLeasebackTransactionDescriptionAxis" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionNameDomain" xlink:label="SaleLeasebackTransactionNameDomain" xlink:title="SaleLeasebackTransactionNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="SaleLeasebackTransactionDescriptionAxis" xlink:to="SaleLeasebackTransactionNameDomain" xlink:title="definition: SaleLeasebackTransactionDescriptionAxis to SaleLeasebackTransactionNameDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleLeasebackTransactionNameDomain" xlink:label="SaleLeasebackTransactionNameDomain_2" xlink:title="SaleLeasebackTransactionNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="SaleLeasebackTransactionDescriptionAxis" xlink:to="SaleLeasebackTransactionNameDomain_2" xlink:title="definition: SaleLeasebackTransactionDescriptionAxis to SaleLeasebackTransactionNameDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_NavigareLeaseMember" xlink:label="NavigareLeaseMember" xlink:title="NavigareLeaseMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SaleLeasebackTransactionNameDomain" xlink:to="NavigareLeaseMember" xlink:title="definition: SaleLeasebackTransactionNameDomain to NavigareLeaseMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="PropertyPlantAndEquipmentByTypeAxis" xlink:title="PropertyPlantAndEquipmentByTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="LesseeLeaseDescriptionTable" xlink:to="PropertyPlantAndEquipmentByTypeAxis" xlink:title="definition: LesseeLeaseDescriptionTable to PropertyPlantAndEquipmentByTypeAxis" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain" xlink:title="definition: PropertyPlantAndEquipmentByTypeAxis to PropertyPlantAndEquipmentTypeDomain" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain_2" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain_2" xlink:title="definition: PropertyPlantAndEquipmentByTypeAxis to PropertyPlantAndEquipmentTypeDomain_2" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_MTEcoBeverlyHillsMember" xlink:label="MTEcoBeverlyHillsMember" xlink:title="MTEcoBeverlyHillsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="MTEcoBeverlyHillsMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to MTEcoBeverlyHillsMember" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_MTEcoBelAirMember" xlink:label="MTEcoBelAirMember" xlink:title="MTEcoBelAirMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="MTEcoBelAirMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to MTEcoBelAirMember" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://topships.org/role/LeasesLeaseArrangementsAsLessorDetails">
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LessorLeaseDescriptionLineItems" xlink:label="LessorLeaseDescriptionLineItems" xlink:title="LessorLeaseDescriptionLineItems" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LessorOperatingLeaseDescriptionAbstract" xlink:label="LessorOperatingLeaseDescriptionAbstract" xlink:title="LessorOperatingLeaseDescriptionAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LessorLeaseDescriptionLineItems" xlink:to="LessorOperatingLeaseDescriptionAbstract" xlink:title="definition: LessorLeaseDescriptionLineItems to LessorOperatingLeaseDescriptionAbstract" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_LessorOperatingLeaseNumberOfVesselsOperatedUnderLeaseAgreements" xlink:label="LessorOperatingLeaseNumberOfVesselsOperatedUnderLeaseAgreements" xlink:title="LessorOperatingLeaseNumberOfVesselsOperatedUnderLeaseAgreements" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LessorLeaseDescriptionLineItems" xlink:to="LessorOperatingLeaseNumberOfVesselsOperatedUnderLeaseAgreements" xlink:title="definition: LessorLeaseDescriptionLineItems to LessorOperatingLeaseNumberOfVesselsOperatedUnderLeaseAgreements" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LessorOperatingLeasePaymentsFiscalYearMaturityAbstract" xlink:label="LessorOperatingLeasePaymentsFiscalYearMaturityAbstract" xlink:title="LessorOperatingLeasePaymentsFiscalYearMaturityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LessorLeaseDescriptionLineItems" xlink:to="LessorOperatingLeasePaymentsFiscalYearMaturityAbstract" xlink:title="definition: LessorLeaseDescriptionLineItems to LessorOperatingLeasePaymentsFiscalYearMaturityAbstract" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:label="LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:title="LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LessorLeaseDescriptionLineItems" xlink:to="LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" xlink:title="definition: LessorLeaseDescriptionLineItems to LessorOperatingLeasePaymentsToBeReceivedNextTwelveMonths" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:label="LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:title="LessorOperatingLeasePaymentsToBeReceivedTwoYears" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LessorLeaseDescriptionLineItems" xlink:to="LessorOperatingLeasePaymentsToBeReceivedTwoYears" xlink:title="definition: LessorLeaseDescriptionLineItems to LessorOperatingLeasePaymentsToBeReceivedTwoYears" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:label="LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:title="LessorOperatingLeasePaymentsToBeReceivedThreeYears" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LessorLeaseDescriptionLineItems" xlink:to="LessorOperatingLeasePaymentsToBeReceivedThreeYears" xlink:title="definition: LessorLeaseDescriptionLineItems to LessorOperatingLeasePaymentsToBeReceivedThreeYears" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:label="LessorOperatingLeasePaymentsToBeReceivedFourYears" xlink:title="LessorOperatingLeasePaymentsToBeReceivedFourYears" />
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    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_LessorOperatingLeasePaymentsToBeReceivedYearFiveAndThereafter" xlink:label="LessorOperatingLeasePaymentsToBeReceivedYearFiveAndThereafter" xlink:title="LessorOperatingLeasePaymentsToBeReceivedYearFiveAndThereafter" />
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    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_WecoTankersASMember" xlink:label="WecoTankersASMember" xlink:title="WecoTankersASMember" />
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    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_ClearlakeShippingPteLtdMember" xlink:label="ClearlakeShippingPteLtdMember" xlink:title="ClearlakeShippingPteLtdMember" />
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    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_TrafiguraMaritimeLogisticsPteLtdMember" xlink:label="TrafiguraMaritimeLogisticsPteLtdMember" xlink:title="TrafiguraMaritimeLogisticsPteLtdMember" />
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    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_DebtInstrumentVesselFinanced" xlink:label="DebtInstrumentVesselFinanced" xlink:title="DebtInstrumentVesselFinanced" />
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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="DebtInstrumentCarryingAmount" xlink:title="DebtInstrumentCarryingAmount" />
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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="DeferredFinanceCostsNet" xlink:title="DeferredFinanceCostsNet" />
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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtByCurrentAndNoncurrentAbstract" xlink:label="LongTermDebtByCurrentAndNoncurrentAbstract" xlink:title="LongTermDebtByCurrentAndNoncurrentAbstract" />
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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtCurrent" xlink:label="LongTermDebtCurrent" xlink:title="LongTermDebtCurrent" />
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    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="LongTermDebtNoncurrent" xlink:title="LongTermDebtNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="DebtInstrumentLineItems" xlink:to="LongTermDebtNoncurrent" xlink:title="definition: DebtInstrumentLineItems to LongTermDebtNoncurrent" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable" xlink:label="DebtInstrumentTable" xlink:title="DebtInstrumentTable" />
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    <link:loc xlink:type="locator" xlink:href="tops-20251231.xsd#tops_TermForMinimumFreeLiquidity" xlink:label="TermForMinimumFreeLiquidity" xlink:title="TermForMinimumFreeLiquidity" />
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