content: <?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
    <!-- Generated by Workiva -->
    <headerData>
      <submissionType>144</submissionType>
      <filerInfo>
        <filer>
          <filerCredentials>
            <cik>0001995218</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001907108</issuerCik>
        <issuerName>Lexeo Therapeutics, Inc.</issuerName>
        <secFileNumber>001-41855</secFileNumber>
        <issuerAddress>
          <com:street1>345 Park Avenue South,  6th Floor</com:street1>
          <com:city>New York</com:city>
          <com:stateOrCountry>NY</com:stateOrCountry>
          <com:zipCode>10010</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>212-547-9879</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Richard Nolan Townsend</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Director</relationshipToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>J.P. Morgan Securities LLC</name>
          <address>
            <com:street1>390 Madison Avenue, 6th Floor</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10017</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>2500</noOfUnitsSold>
        <aggregateMarketValue>20600</aggregateMarketValue>
        <noOfUnitsOutstanding>33065947</noOfUnitsOutstanding>
        <approxSaleDate>12/10/2024</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>12/10/2024</acquiredDate>
        <natureOfAcquisitionTransaction>Stock Option Exercise</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>2500</amountOfSecuritiesAcquired>
        <paymentDate>12/10/2024</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Richard Nolan Townsend</name>
          <address>
            <com:street1>C/o Lexeo Therapeutics, Inc.</com:street1>
            <com:street2>345 Park Avenue South, 6th Floor</com:street2>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10010</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>10/10/2024</saleDate>
        <amountOfSecuritiesSold>5000</amountOfSecuritiesSold>
        <grossProceeds>40495</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>Richard Nolan Townsend</name>
          <address>
            <com:street1>C/o Lexeo Therapeutics, Inc.</com:street1>
            <com:street2>345 Park Avenue South, 6th Floor</com:street2>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10010</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>11/11/2024</saleDate>
        <amountOfSecuritiesSold>2500</amountOfSecuritiesSold>
        <grossProceeds>19557</grossProceeds>
      </securitiesSoldInPast3Months>
      <remarks>The  shares covered by this filing are stock options that will be exercised within 3 months from the date of this filing.</remarks>
      <noticeSignature>
        <noticeDate>12/10/2024</noticeDate>
        <planAdoptionDates>
          <planAdoptionDate>12/19/2023</planAdoptionDate>
        </planAdoptionDates>
        <signature>/s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Richard Nolan Townsend</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
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text: 144
  0001995218
  XXXXXXXX
  LIVE
  0001907108
  Lexeo Therapeutics, Inc.
  001-41855
  345 Park Avenue South,  6th Floor
  New York
  NY
  10010
  212-547-9879
  Richard Nolan Townsend
  Director
  Officer
  Common Stock
  J.P. Morgan Securities LLC
  390 Madison Avenue, 6th Floor
  New York
  NY
  10017
  2500
  20600
  33065947
  12/10/2024
  NASDAQ
  Common Stock
  12/10/2024
  Stock Option Exercise
  Issuer
  N
  2500
  12/10/2024
  Cash
  N
  Richard Nolan Townsend
  C/o Lexeo Therapeutics, Inc.
  345 Park Avenue South, 6th Floor
  New York
  NY
  10010
  Common Stock
  10/10/2024
  5000
  40495
  Richard Nolan Townsend
  C/o Lexeo Therapeutics, Inc.
  345 Park Avenue South, 6th Floor
  New York
  NY
  10010
  Common Stock
  11/11/2024
  2500
  19557
  The  shares covered by this filing are stock options that will be exercised within 3 months from the date of this filing.
  12/10/2024
  12/19/2023
  /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Richard Nolan Townsend