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    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001973580</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001060955</issuerCik>
            <issuerName>ICON PLC</issuerName>
            <secFileNumber>333-08704</secFileNumber>
            <issuerAddress>
                <ns2:street1>South County Business Park</ns2:street1>
                <ns2:street2>Leopardstown</ns2:street2>
                <ns2:city>Dublin 18</ns2:city>
                <ns2:stateOrCountry>L2</ns2:stateOrCountry>
                <ns2:zipCode>D18 X5R3</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>353-1-291-2000</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>BRENDAN BRENNAN</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>1582</noOfUnitsSold>
            <aggregateMarketValue>510594.30</aggregateMarketValue>
            <noOfUnitsOutstanding>82495086</noOfUnitsOutstanding>
            <approxSaleDate>03/04/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/03/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>321</amountOfSecuritiesAcquired>
            <paymentDate>03/06/2024</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/03/2021</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>372</amountOfSecuritiesAcquired>
            <paymentDate>03/06/2024</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/03/2021</acquiredDate>
            <natureOfAcquisitionTransaction>Performance Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>558</amountOfSecuritiesAcquired>
            <paymentDate>03/06/2024</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/03/2022</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>331</amountOfSecuritiesAcquired>
            <paymentDate>03/06/2024</paymentDate>
            <natureOfPayment>Services Rendered</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>BRENDAN BRENNAN</name>
                <address>
                    <ns2:street1>South County Business Park</ns2:street1>
                    <ns2:street2>Leopardstown</ns2:street2>
                    <ns2:city>Dublin 18</ns2:city>
                    <ns2:stateOrCountry>L2</ns2:stateOrCountry>
                    <ns2:zipCode>D18 X5R3</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>02/26/2024</saleDate>
            <amountOfSecuritiesSold>7021</amountOfSecuritiesSold>
            <grossProceeds>2220929.06</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>Date of Plan Adoption or Giving of Instruction, if
Relying on Rule 10b5-1
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing
this notice that he does not know any material adverse information in regard to the current and prospective
operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has
adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing
the form and indicating the date that the plan was adopted or the instruction given, that person makes such
representation as of the plan adoption or instruction date.
Signature
19 September 2023</remarks>
        <noticeSignature>
            <noticeDate>03/04/2024</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Brendan Brennan</signature>
        </noticeSignature>
    </formData>
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144
0001973580
XXXXXXXX
LIVE
0001060955
ICON PLC
333-08704
South County Business Park
Leopardstown
Dublin 18
L2
D18 X5R3
353-1-291-2000
BRENDAN BRENNAN
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
1582
510594.30
82495086
03/04/2024
NASDAQ
Common
03/03/2023
Restricted stock vesting under a registered plan
Issuer
N
321
03/06/2024
Services Rendered
Common
03/03/2021
Restricted stock vesting under a registered plan
Issuer
N
372
03/06/2024
Services Rendered
Common
03/03/2021
Performance Stock Units
Issuer
N
558
03/06/2024
Services Rendered
Common
03/03/2022
Restricted stock vesting under a registered plan
Issuer
N
331
03/06/2024
Services Rendered
N
BRENDAN BRENNAN
South County Business Park
Leopardstown
Dublin 18
L2
D18 X5R3
Common
02/26/2024
7021
2220929.06
Date of Plan Adoption or Giving of Instruction, if
Relying on Rule 10b5-1
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing
this notice that he does not know any material adverse information in regard to the current and prospective
operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has
adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing
the form and indicating the date that the plan was adopted or the instruction given, that person makes such
representation as of the plan adoption or instruction date.
Signature
19 September 2023
03/04/2024
/s/ Brendan Brennan