<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019e8950-ddc1-75c9-9110-3cb9cfad04cb,g:21bc77ad-0be6-45a0-9820-e4d8995d3588-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://iradimed.com/role/CONDENSEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="irmd-20260630.xsd#CONDENSEDSTATEMENTSOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/CONDENSEDSTATEMENTSOFSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019e8950-ddc1-7ba5-a994-973666a3cc32" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019e8950-ddc1-715e-b506-3e79a1c5506d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019e8950-ddc1-7ba5-a994-973666a3cc32" xlink:to="loc_us-gaap_StatementTable_019e8950-ddc1-715e-b506-3e79a1c5506d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019e8950-ddc1-7769-ab56-29ded8c904f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019e8950-ddc1-715e-b506-3e79a1c5506d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019e8950-ddc1-7769-ab56-29ded8c904f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8950-ddc1-7769-ab56-29ded8c904f8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8950-ddc1-7769-ab56-29ded8c904f8" xlink:to="loc_us-gaap_EquityComponentDomain_019e8950-ddc1-7769-ab56-29ded8c904f8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019e8950-ddc1-7c74-8c5f-3a6f60992328" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019e8950-ddc1-7769-ab56-29ded8c904f8" xlink:to="loc_us-gaap_EquityComponentDomain_019e8950-ddc1-7c74-8c5f-3a6f60992328" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019e8950-ddc1-74a7-a0df-62ffdfd8951e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8950-ddc1-7c74-8c5f-3a6f60992328" xlink:to="loc_us-gaap_CommonStockMember_019e8950-ddc1-74a7-a0df-62ffdfd8951e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019e8950-ddc1-72ca-8760-82b16266e2fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8950-ddc1-7c74-8c5f-3a6f60992328" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019e8950-ddc1-72ca-8760-82b16266e2fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019e8950-ddc1-79a9-a39c-3394afd37c7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019e8950-ddc1-7c74-8c5f-3a6f60992328" xlink:to="loc_us-gaap_RetainedEarningsMember_019e8950-ddc1-79a9-a39c-3394afd37c7c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019e8950-ddc1-7ba5-a994-973666a3cc32" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_019e8950-ddc1-734c-a0d2-2a1032e54114" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:to="loc_us-gaap_SharesOutstanding_019e8950-ddc1-734c-a0d2-2a1032e54114" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e8950-ddc1-79e5-843a-6671e84287de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:to="loc_us-gaap_StockholdersEquity_019e8950-ddc1-79e5-843a-6671e84287de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019e8950-ddc1-7c57-b06e-34f5f2014154" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:to="loc_us-gaap_NetIncomeLoss_019e8950-ddc1-7c57-b06e-34f5f2014154" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_019e8950-ddc1-7e2c-86a5-495842d302aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:to="loc_us-gaap_DividendsCommonStock_019e8950-ddc1-7e2c-86a5-495842d302aa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e8950-ddc1-7e8c-a68c-6c23e9f22341" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019e8950-ddc1-7e8c-a68c-6c23e9f22341" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_019e8950-ddc1-7c9b-bd61-64218b21ec92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:to="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_019e8950-ddc1-7c9b-bd61-64218b21ec92" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_019e8950-ddc1-7dfd-8b93-136b7b444a62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019e8950-ddc1-7711-9bb1-41e63ee655d8" xlink:to="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_019e8950-ddc1-7dfd-8b93-136b7b444a62" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_019e8950-ddc1-74ba-82ef-e9fe8e05f45f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019e8950-ddc1-7b9b-8146-8e86c708da70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/RevenueRecognitionScheduleofDisaggregationofRevenuebyGeographicRegionDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#RevenueRecognitionScheduleofDisaggregationofRevenuebyGeographicRegionDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/RevenueRecognitionScheduleofDisaggregationofRevenuebyGeographicRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019e8950-de7c-7853-8cc6-ce8d655ba852" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019e8950-de7c-7473-89f3-de9ffb2a8c92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e8950-de7c-7853-8cc6-ce8d655ba852" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019e8950-de7c-7473-89f3-de9ffb2a8c92" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019e8950-de7c-764f-9907-d4a45303e173" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e8950-de7c-7473-89f3-de9ffb2a8c92" xlink:to="loc_srt_StatementGeographicalAxis_019e8950-de7c-764f-9907-d4a45303e173" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8950-de7c-764f-9907-d4a45303e173_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019e8950-de7c-764f-9907-d4a45303e173" xlink:to="loc_srt_SegmentGeographicalDomain_019e8950-de7c-764f-9907-d4a45303e173_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8950-de7c-703a-a80a-723a4a8524d1" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019e8950-de7c-764f-9907-d4a45303e173" xlink:to="loc_srt_SegmentGeographicalDomain_019e8950-de7c-703a-a80a-723a4a8524d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019e8950-de7c-79cf-b2a1-3e7e473e6d48" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8950-de7c-703a-a80a-723a4a8524d1" xlink:to="loc_country_US_019e8950-de7c-79cf-b2a1-3e7e473e6d48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_019e8950-de7c-7260-88b2-435a064c7cef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8950-de7c-703a-a80a-723a4a8524d1" xlink:to="loc_us-gaap_NonUsMember_019e8950-de7c-7260-88b2-435a064c7cef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8950-de7c-71be-8f41-40a26dcceafe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e8950-de7c-7853-8cc6-ce8d655ba852" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8950-de7c-71be-8f41-40a26dcceafe" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/RevenueRecognitionScheduleofRevenueInformationbyTypeDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#RevenueRecognitionScheduleofRevenueInformationbyTypeDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/RevenueRecognitionScheduleofRevenueInformationbyTypeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_019e8950-de7c-7906-aaaf-c58a02355e56" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_019e8950-de7c-7c26-b5bb-b3d0adcf6f8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e8950-de7c-7906-aaaf-c58a02355e56" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019e8950-de7c-7c26-b5bb-b3d0adcf6f8a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019e8950-de7c-76da-a65e-2f0a4d6e6ee7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_019e8950-de7c-7c26-b5bb-b3d0adcf6f8a" xlink:to="loc_srt_ProductOrServiceAxis_019e8950-de7c-76da-a65e-2f0a4d6e6ee7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e8950-de7c-76da-a65e-2f0a4d6e6ee7_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_019e8950-de7c-76da-a65e-2f0a4d6e6ee7" xlink:to="loc_srt_ProductsAndServicesDomain_019e8950-de7c-76da-a65e-2f0a4d6e6ee7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019e8950-de7c-75d3-b6ab-5dd482762cc3" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_019e8950-de7c-76da-a65e-2f0a4d6e6ee7" xlink:to="loc_srt_ProductsAndServicesDomain_019e8950-de7c-75d3-b6ab-5dd482762cc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_DeviceRevenueMember_019e8950-de7c-7316-85ab-e370cd623a9a" xlink:href="irmd-20260630.xsd#irmd_DeviceRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8950-de7c-75d3-b6ab-5dd482762cc3" xlink:to="loc_irmd_DeviceRevenueMember_019e8950-de7c-7316-85ab-e370cd623a9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_MRICompatibleIVInfusionPumpsMember_019e8950-de7c-7eef-a8d0-486b3473fcc3" xlink:href="irmd-20260630.xsd#irmd_MRICompatibleIVInfusionPumpsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_irmd_DeviceRevenueMember_019e8950-de7c-7316-85ab-e370cd623a9a" xlink:to="loc_irmd_MRICompatibleIVInfusionPumpsMember_019e8950-de7c-7eef-a8d0-486b3473fcc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_MRICompatiblePatientVitalSignsMonitoringSystemsMember_019e8950-de7c-70c7-8a77-f2d41226ea6f" xlink:href="irmd-20260630.xsd#irmd_MRICompatiblePatientVitalSignsMonitoringSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_irmd_DeviceRevenueMember_019e8950-de7c-7316-85ab-e370cd623a9a" xlink:to="loc_irmd_MRICompatiblePatientVitalSignsMonitoringSystemsMember_019e8950-de7c-70c7-8a77-f2d41226ea6f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_FerroMagneticDetectionSystemsMember_019e8950-de7c-71c1-ae8b-cd74ff2ba5ca" xlink:href="irmd-20260630.xsd#irmd_FerroMagneticDetectionSystemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_irmd_DeviceRevenueMember_019e8950-de7c-7316-85ab-e370cd623a9a" xlink:to="loc_irmd_FerroMagneticDetectionSystemsMember_019e8950-de7c-71c1-ae8b-cd74ff2ba5ca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_AmortizedRevenueMember_019e8950-de7c-742c-95e4-dca6d06527d3" xlink:href="irmd-20260630.xsd#irmd_AmortizedRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8950-de7c-75d3-b6ab-5dd482762cc3" xlink:to="loc_irmd_AmortizedRevenueMember_019e8950-de7c-742c-95e4-dca6d06527d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_DisposableRevenueMember_019e8950-de7c-71bf-8b61-cb1d8a332ec5" xlink:href="irmd-20260630.xsd#irmd_DisposableRevenueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8950-de7c-75d3-b6ab-5dd482762cc3" xlink:to="loc_irmd_DisposableRevenueMember_019e8950-de7c-71bf-8b61-cb1d8a332ec5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_019e8950-de7c-764e-8807-7e3d96b70d41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019e8950-de7c-75d3-b6ab-5dd482762cc3" xlink:to="loc_us-gaap_ServiceMember_019e8950-de7c-764e-8807-7e3d96b70d41" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8950-de7c-7aba-abdf-c4e41877cc2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_019e8950-de7c-7906-aaaf-c58a02355e56" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019e8950-de7c-7aba-abdf-c4e41877cc2a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/PropertyandEquipmentnetScheduleofPropertyandEquipmentDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#PropertyandEquipmentnetScheduleofPropertyandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/PropertyandEquipmentnetScheduleofPropertyandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-77c9-b5a7-637497052cfa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e8950-de7c-7e3b-be58-01f41c39acfc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-77c9-b5a7-637497052cfa" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e8950-de7c-7e3b-be58-01f41c39acfc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e8950-de7c-7dd1-b321-a0c292e99c6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e8950-de7c-7e3b-be58-01f41c39acfc" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e8950-de7c-7dd1-b321-a0c292e99c6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-7dd1-b321-a0c292e99c6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e8950-de7c-7dd1-b321-a0c292e99c6f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-7dd1-b321-a0c292e99c6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019e8950-de7c-7dd1-b321-a0c292e99c6f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandMember_019e8950-de7c-7201-b6b5-5f63d007d52b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:to="loc_us-gaap_LandMember_019e8950-de7c-7201-b6b5-5f63d007d52b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandImprovementsMember_019e8950-de7c-7364-9e87-a5f2ef80a5ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LandImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:to="loc_us-gaap_LandImprovementsMember_019e8950-de7c-7364-9e87-a5f2ef80a5ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_019e8950-de7c-7284-bfb7-2a4050577626" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:to="loc_us-gaap_BuildingMember_019e8950-de7c-7284-bfb7-2a4050577626" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_ComputerSoftwareAndHardwareMember_019e8950-de7c-7077-9cac-ec7d3934d065" xlink:href="irmd-20260630.xsd#irmd_ComputerSoftwareAndHardwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:to="loc_irmd_ComputerSoftwareAndHardwareMember_019e8950-de7c-7077-9cac-ec7d3934d065" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_019e8950-de7c-7ec8-aa3e-dfce72d796a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_019e8950-de7c-7ec8-aa3e-dfce72d796a4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_019e8950-de7c-7d40-abed-582c2d05939c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_019e8950-de7c-7d40-abed-582c2d05939c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_019e8950-de7c-7ca9-9c00-65ccca50104a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019e8950-de7c-76bd-a6ab-b46bdc597e3e" xlink:to="loc_us-gaap_ConstructionInProgressMember_019e8950-de7c-7ca9-9c00-65ccca50104a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019e8950-de7c-73dd-8e56-52005882ba30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-77c9-b5a7-637497052cfa" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019e8950-de7c-73dd-8e56-52005882ba30" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019e8950-de7c-7b3e-9006-0770ea9d1eac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-77c9-b5a7-637497052cfa" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019e8950-de7c-7b3e-9006-0770ea9d1eac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019e8950-de7c-72a8-ab68-05df47cd6095" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-77c9-b5a7-637497052cfa" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019e8950-de7c-72a8-ab68-05df47cd6095" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/PropertyandEquipmentnetScheduleofGeographicRegionDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#PropertyandEquipmentnetScheduleofGeographicRegionDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/PropertyandEquipmentnetScheduleofGeographicRegionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-711b-88e4-2348d52d6b45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e8950-de7c-7528-87b5-790c9a21bfc2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-711b-88e4-2348d52d6b45" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e8950-de7c-7528-87b5-790c9a21bfc2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019e8950-de7c-730a-b156-8b99d2e56492" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_019e8950-de7c-7528-87b5-790c9a21bfc2" xlink:to="loc_srt_StatementGeographicalAxis_019e8950-de7c-730a-b156-8b99d2e56492" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8950-de7c-730a-b156-8b99d2e56492_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_019e8950-de7c-730a-b156-8b99d2e56492" xlink:to="loc_srt_SegmentGeographicalDomain_019e8950-de7c-730a-b156-8b99d2e56492_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019e8950-de7c-7484-a501-c428567838ee" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_019e8950-de7c-730a-b156-8b99d2e56492" xlink:to="loc_srt_SegmentGeographicalDomain_019e8950-de7c-7484-a501-c428567838ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019e8950-de7c-7662-9b26-8f72586f8ad4" xlink:href="https://xbrl.sec.gov/country/2026/country-2026.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8950-de7c-7484-a501-c428567838ee" xlink:to="loc_country_US_019e8950-de7c-7662-9b26-8f72586f8ad4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_019e8950-de7c-7adf-8c5d-ebea7d33673c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_019e8950-de7c-7484-a501-c428567838ee" xlink:to="loc_us-gaap_NonUsMember_019e8950-de7c-7adf-8c5d-ebea7d33673c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019e8950-de7c-7570-992b-6ea19631c5eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_019e8950-de7c-711b-88e4-2348d52d6b45" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019e8950-de7c-7570-992b-6ea19631c5eb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/IntangibleAssetsnetScheduleofComponentsofIntangibleAssetsDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#IntangibleAssetsnetScheduleofComponentsofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/IntangibleAssetsnetScheduleofComponentsofIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8950-de7c-7952-ba54-4f2d44b1d37e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019e8950-de7c-73de-ac22-bf622e267e7d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8950-de7c-7952-ba54-4f2d44b1d37e" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019e8950-de7c-73de-ac22-bf622e267e7d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8950-de7c-7374-8076-acea1e5c4b76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_019e8950-de7c-73de-ac22-bf622e267e7d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8950-de7c-7374-8076-acea1e5c4b76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-7374-8076-acea1e5c4b76_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8950-de7c-7374-8076-acea1e5c4b76" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-7374-8076-acea1e5c4b76_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019e8950-de7c-7374-8076-acea1e5c4b76" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_PatentsInUseMember_019e8950-de7c-7575-bfc1-a1daa9295cdf" xlink:href="irmd-20260630.xsd#irmd_PatentsInUseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:to="loc_irmd_PatentsInUseMember_019e8950-de7c-7575-bfc1-a1daa9295cdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_PatentsFullyAmortizedMember_019e8950-de7c-7552-8034-841d594da95e" xlink:href="irmd-20260630.xsd#irmd_PatentsFullyAmortizedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:to="loc_irmd_PatentsFullyAmortizedMember_019e8950-de7c-7552-8034-841d594da95e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_PatentsInProcessMember_019e8950-de7c-7265-90ff-ea4e04feec33" xlink:href="irmd-20260630.xsd#irmd_PatentsInProcessMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:to="loc_irmd_PatentsInProcessMember_019e8950-de7c-7265-90ff-ea4e04feec33" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_InternallyDevelopedSoftwareInUseMember_019e8950-de7c-7e98-83ce-d4194fb92aa7" xlink:href="irmd-20260630.xsd#irmd_InternallyDevelopedSoftwareInUseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:to="loc_irmd_InternallyDevelopedSoftwareInUseMember_019e8950-de7c-7e98-83ce-d4194fb92aa7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_InternallyDevelopedSoftwareInProcessMember_019e8950-de7c-713c-8391-35a5f34caf65" xlink:href="irmd-20260630.xsd#irmd_InternallyDevelopedSoftwareInProcessMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:to="loc_irmd_InternallyDevelopedSoftwareInProcessMember_019e8950-de7c-713c-8391-35a5f34caf65" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksMember_019e8950-de7c-7310-a045-519a509254bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TrademarksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019e8950-de7c-71b4-8105-11ca395bcd8a" xlink:to="loc_us-gaap_TrademarksMember_019e8950-de7c-7310-a045-519a509254bd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019e8950-de7c-7da5-aa49-1bba896a2ccf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8950-de7c-7952-ba54-4f2d44b1d37e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_019e8950-de7c-7da5-aa49-1bba896a2ccf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019e8950-de7c-7e28-9941-fbc115acbb1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8950-de7c-7952-ba54-4f2d44b1d37e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_019e8950-de7c-7e28-9941-fbc115acbb1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019e8950-de7c-7d3b-99fe-eb76ea3eefd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_019e8950-de7c-7952-ba54-4f2d44b1d37e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_019e8950-de7c-7d3b-99fe-eb76ea3eefd4" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/FairValueMeasurementsDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#FairValueMeasurementsDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/FairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8950-de7c-75f5-bbe3-7a1b34d033cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8950-de7c-76ee-b982-a4b7533d92d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8950-de7c-75f5-bbe3-7a1b34d033cd" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8950-de7c-76ee-b982-a4b7533d92d1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019e8950-de7c-73ee-b905-e246ff754981" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019e8950-de7c-76ee-b982-a4b7533d92d1" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019e8950-de7c-73ee-b905-e246ff754981" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019e8950-de7c-73ee-b905-e246ff754981_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019e8950-de7c-73ee-b905-e246ff754981" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019e8950-de7c-73ee-b905-e246ff754981_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_019e8950-de7c-7541-91bd-90f452ada338" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_019e8950-de7c-73ee-b905-e246ff754981" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_019e8950-de7c-7541-91bd-90f452ada338" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_019e8950-de7c-7bb8-8a51-d3ccec456ad3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_019e8950-de7c-7541-91bd-90f452ada338" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_019e8950-de7c-7bb8-8a51-d3ccec456ad3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019e8950-de7c-7d8a-a708-f59c3f9cbc99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8950-de7c-75f5-bbe3-7a1b34d033cd" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_019e8950-de7c-7d8a-a708-f59c3f9cbc99" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_019e8950-de7c-7ffc-b95f-6183f5d7564f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019e8950-de7c-75f5-bbe3-7a1b34d033cd" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_019e8950-de7c-7ffc-b95f-6183f5d7564f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/StockBasedCompensationScheduleofStockBasedCompensationExpenseDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#StockBasedCompensationScheduleofStockBasedCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/StockBasedCompensationScheduleofStockBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8950-de7c-7723-9662-60393ef24d99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8950-de7c-7057-a573-9f486e80c019" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8950-de7c-7723-9662-60393ef24d99" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8950-de7c-7057-a573-9f486e80c019" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e8950-de7c-75e7-892a-348fb033e396" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8950-de7c-7057-a573-9f486e80c019" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019e8950-de7c-75e7-892a-348fb033e396" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8950-de7c-7b42-9a83-3a3920edb0e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8950-de7c-7723-9662-60393ef24d99" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8950-de7c-7b42-9a83-3a3920edb0e9" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/StockBasedCompensationScheduleofStockBasedCompensationExpenseDetails_1" xlink:type="simple" xlink:href="irmd-20260630.xsd#StockBasedCompensationScheduleofStockBasedCompensationExpenseDetails_1"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/StockBasedCompensationScheduleofStockBasedCompensationExpenseDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8950-de7c-7723-9662-60393ef24d99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8950-de7c-7057-a573-9f486e80c019" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8950-de7c-7723-9662-60393ef24d99" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_019e8950-de7c-7057-a573-9f486e80c019" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8950-de7c-7b42-9a83-3a3920edb0e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_019e8950-de7c-7723-9662-60393ef24d99" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019e8950-de7c-7b42-9a83-3a3920edb0e9" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/StockBasedCompensationAdditionalInformationDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#StockBasedCompensationAdditionalInformationDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/StockBasedCompensationAdditionalInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e8950-de7c-7d5f-ae5d-1ad6b1b90210" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e8950-de7c-72b6-ac7b-1aa764b8fe5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e8950-de7c-7d5f-ae5d-1ad6b1b90210" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e8950-de7c-72b6-ac7b-1aa764b8fe5c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e8950-de7c-7c4f-af9c-95a6679c8f96" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e8950-de7c-72b6-ac7b-1aa764b8fe5c" xlink:to="loc_us-gaap_AwardTypeAxis_019e8950-de7c-7c4f-af9c-95a6679c8f96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-7c4f-af9c-95a6679c8f96_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e8950-de7c-7c4f-af9c-95a6679c8f96" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-7c4f-af9c-95a6679c8f96_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-75d2-9a4c-6bda3b1ac668" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e8950-de7c-7c4f-af9c-95a6679c8f96" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-75d2-9a4c-6bda3b1ac668" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e8950-de7c-7ced-bbd2-546383c8d176" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-75d2-9a4c-6bda3b1ac668" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e8950-de7c-7ced-bbd2-546383c8d176" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_PerformanceBasedRestrictedStockUnitsMember_019e8950-de7c-7aab-8b38-6ebb3f071038" xlink:href="irmd-20260630.xsd#irmd_PerformanceBasedRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-75d2-9a4c-6bda3b1ac668" xlink:to="loc_irmd_PerformanceBasedRestrictedStockUnitsMember_019e8950-de7c-7aab-8b38-6ebb3f071038" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019e8950-de7c-7650-a12f-b236f7a4efe5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e8950-de7c-7d5f-ae5d-1ad6b1b90210" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019e8950-de7c-7650-a12f-b236f7a4efe5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019e8950-de7c-72a9-90f8-7aee905052c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e8950-de7c-7d5f-ae5d-1ad6b1b90210" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019e8950-de7c-72a9-90f8-7aee905052c1" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/StockBasedCompensationScheduleofEquityAwardActivityDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#StockBasedCompensationScheduleofEquityAwardActivityDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/StockBasedCompensationScheduleofEquityAwardActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e8950-de7c-7ca6-8a57-5b67ab7903fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e8950-de7c-7ec7-a539-ad17bd3b0f72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e8950-de7c-7ca6-8a57-5b67ab7903fc" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e8950-de7c-7ec7-a539-ad17bd3b0f72" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019e8950-de7c-763e-b4fc-dda6d188f66d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019e8950-de7c-7ec7-a539-ad17bd3b0f72" xlink:to="loc_us-gaap_AwardTypeAxis_019e8950-de7c-763e-b4fc-dda6d188f66d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-763e-b4fc-dda6d188f66d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_019e8950-de7c-763e-b4fc-dda6d188f66d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-763e-b4fc-dda6d188f66d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-721c-9769-941a5a2b7a7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_019e8950-de7c-763e-b4fc-dda6d188f66d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-721c-9769-941a5a2b7a7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_019e8950-de7c-7370-bd1b-30bf04cce621" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-721c-9769-941a5a2b7a7f" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_019e8950-de7c-7370-bd1b-30bf04cce621" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_irmd_PerformanceBasedRestrictedStockUnitsMember_019e8950-de7c-7ecc-a694-5f913b473c1d" xlink:href="irmd-20260630.xsd#irmd_PerformanceBasedRestrictedStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019e8950-de7c-721c-9769-941a5a2b7a7f" xlink:to="loc_irmd_PerformanceBasedRestrictedStockUnitsMember_019e8950-de7c-7ecc-a694-5f913b473c1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_019e8950-de7c-7585-9e17-6f70d56b6f9b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019e8950-de7c-7ca6-8a57-5b67ab7903fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_019e8950-de7c-7585-9e17-6f70d56b6f9b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_019e8950-de7c-7138-913f-366810300fe2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_019e8950-de7c-7585-9e17-6f70d56b6f9b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_019e8950-de7c-7138-913f-366810300fe2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019e8950-de7c-71dd-b98c-fd64583c96a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_019e8950-de7c-7585-9e17-6f70d56b6f9b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_019e8950-de7c-71dd-b98c-fd64583c96a7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_019e8950-de7c-7345-abce-4eddf28eae6c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_019e8950-de7c-7585-9e17-6f70d56b6f9b" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_019e8950-de7c-7345-abce-4eddf28eae6c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_019f8678-b610-73c7-9c10-e3389c47bd16" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_019e8950-de7c-7585-9e17-6f70d56b6f9b" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_019f8678-b610-73c7-9c10-e3389c47bd16" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_019e8950-de7c-77d5-8411-5b038005518b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://iradimed.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="irmd-20260630.xsd#SubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://iradimed.com/role/SubsequentEventsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019e8950-de7c-70e8-b236-3bc18bcd5320" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019e8950-de7c-70f0-864c-2358ad0fbea2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019e8950-de7c-70e8-b236-3bc18bcd5320" xlink:to="loc_us-gaap_SubsequentEventTable_019e8950-de7c-70f0-864c-2358ad0fbea2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019e8950-de7c-7d94-8f35-b120b4aff66e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019e8950-de7c-70f0-864c-2358ad0fbea2" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019e8950-de7c-7d94-8f35-b120b4aff66e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019e8950-de7c-7d94-8f35-b120b4aff66e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019e8950-de7c-7d94-8f35-b120b4aff66e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019e8950-de7c-7d94-8f35-b120b4aff66e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019e8950-de7c-777f-b731-bce5713cdb66" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019e8950-de7c-7d94-8f35-b120b4aff66e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019e8950-de7c-777f-b731-bce5713cdb66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019e8950-de7c-7a4c-bf02-8f7fc72d793f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019e8950-de7c-777f-b731-bce5713cdb66" xlink:to="loc_us-gaap_SubsequentEventMember_019e8950-de7c-7a4c-bf02-8f7fc72d793f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019e8950-de7c-75f3-b23a-d4d2a9b66ac0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019e8950-de7c-70e8-b236-3bc18bcd5320" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019e8950-de7c-75f3-b23a-d4d2a9b66ac0" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
