<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <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>7930</noOfUnitsSold>
            <aggregateMarketValue>2509319.24</aggregateMarketValue>
            <noOfUnitsOutstanding>82683805</noOfUnitsOutstanding>
            <approxSaleDate>05/10/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/03/2019</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>324</amountOfSecuritiesAcquired>
            <paymentDate>03/03/2019</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/03/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1392</amountOfSecuritiesAcquired>
            <paymentDate>03/03/2024</paymentDate>
            <natureOfPayment>Not Applicable</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>634</amountOfSecuritiesAcquired>
            <paymentDate>03/03/2022</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <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>3278</amountOfSecuritiesAcquired>
            <paymentDate>03/03/2023</paymentDate>
            <natureOfPayment>Not Applicable</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/03/2020</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted stock vesting under a registered plan</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>1453</amountOfSecuritiesAcquired>
            <paymentDate>03/03/2020</paymentDate>
            <natureOfPayment>Not Applicable</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>849</amountOfSecuritiesAcquired>
            <paymentDate>03/03/2021</paymentDate>
            <natureOfPayment>Not Applicable</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>03/04/2024</saleDate>
            <amountOfSecuritiesSold>1582</amountOfSecuritiesSold>
            <grossProceeds>510594.30</grossProceeds>
        </securitiesSoldInPast3Months>
        <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>
        <noticeSignature>
            <noticeDate>05/10/2024</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Brendan Brennan</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 7926}]
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
7930
2509319.24
82683805
05/10/2024
NASDAQ
Common
03/03/2019
Restricted stock vesting under a registered plan
Issuer
N
324
03/03/2019
Not Applicable
Common
03/03/2024
Restricted stock vesting under a registered plan
Issuer
N
1392
03/03/2024
Not Applicable
Common
03/03/2022
Restricted stock vesting under a registered plan
Issuer
N
634
03/03/2022
Not Applicable
Common
03/03/2023
Restricted stock vesting under a registered plan
Issuer
N
3278
03/03/2023
Not Applicable
Common
03/03/2020
Restricted stock vesting under a registered plan
Issuer
N
1453
03/03/2020
Not Applicable
Common
03/03/2021
Restricted stock vesting under a registered plan
Issuer
N
849
03/03/2021
Not Applicable
N
BRENDAN BRENNAN
South County Business Park
Leopardstown
Dublin 18
L2
D18 X5R3
Common
03/04/2024
1582
510594.30
BRENDAN BRENNAN
South County Business Park
Leopardstown
Dublin 18
L2
D18 X5R3
Common
02/26/2024
7021
2220929.06
05/10/2024
/s/ Brendan Brennan