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>0001204576</cik>
            <ccc>XXXXXXXX</ccc>
          </filerCredentials>
        </filer>
        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
      </filerInfo>
    </headerData>
    <formData>
      <issuerInfo>
        <issuerCik>0001519061</issuerCik>
        <issuerName>Trinseo PLC</issuerName>
        <secFileNumber>001-36473</secFileNumber>
        <issuerAddress>
          <com:street1>440 East Swedesford Road, Ste. 301</com:street1>
          <com:city>Wayne</com:city>
          <com:stateOrCountry>PA</com:stateOrCountry>
          <com:zipCode>19087</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>610-240-3200</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Mark Tomkins</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Affiliate</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>11142</noOfUnitsSold>
        <aggregateMarketValue>27632.16</aggregateMarketValue>
        <noOfUnitsOutstanding>35356020</noOfUnitsOutstanding>
        <approxSaleDate>08/13/2024</approxSaleDate>
        <securitiesExchangeName>NYSE</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>08/05/2019</acquiredDate>
        <natureOfAcquisitionTransaction>Open Market Purchase</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Open Market</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>2800</amountOfSecuritiesAcquired>
        <paymentDate>08/05/2019</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>06/09/2021</acquiredDate>
        <natureOfAcquisitionTransaction>RSU Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>4955</amountOfSecuritiesAcquired>
        <paymentDate>06/09/2021</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>06/17/2022</acquiredDate>
        <natureOfAcquisitionTransaction>RSU Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>1147</amountOfSecuritiesAcquired>
        <paymentDate>06/17/2022</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>06/14/2023</acquiredDate>
        <natureOfAcquisitionTransaction>RSU Vesting</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>2240</amountOfSecuritiesAcquired>
        <paymentDate>06/14/2023</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>08/13/2024</noticeDate>
        <signature>/s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Mark Tomkins</signature>
      </noticeSignature>
    </formData>
  </edgarSubmission>
metadata_documents: [{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4418}]
text: 144
  0001204576
  XXXXXXXX
  LIVE
  0001519061
  Trinseo PLC
  001-36473
  440 East Swedesford Road, Ste. 301
  Wayne
  PA
  19087
  610-240-3200
  Mark Tomkins
  Affiliate
  Common Stock
  J.P. Morgan Securities LLC
  390 Madison Avenue - 6th Floor
  New York
  NY
  10017
  11142
  27632.16
  35356020
  08/13/2024
  NYSE
  Common Stock
  08/05/2019
  Open Market Purchase
  Open Market
  N
  2800
  08/05/2019
  Cash
  Common Stock
  06/09/2021
  RSU Vesting
  Issuer
  N
  4955
  06/09/2021
  Compensation
  Common Stock
  06/17/2022
  RSU Vesting
  Issuer
  N
  1147
  06/17/2022
  Compensation
  Common Stock
  06/14/2023
  RSU Vesting
  Issuer
  N
  2240
  06/14/2023
  Compensation
  Y
  08/13/2024
  /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Mark Tomkins