<?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>0001383731</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001599901</issuerCik>
            <issuerName>AVIDITY BIOSCIENCES INC</issuerName>
            <secFileNumber>001-39321</secFileNumber>
            <issuerAddress>
                <ns2:street1>10578 Science Center Drive, Suite 125</ns2:street1>
                <ns2:city>San Diego</ns2:city>
                <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                <ns2:zipCode>92121</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>8584017900</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>MICHAEL MACLEAN</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>104245</noOfUnitsSold>
            <aggregateMarketValue>3014765.40</aggregateMarketValue>
            <noOfUnitsOutstanding>95636748</noOfUnitsOutstanding>
            <approxSaleDate>06/12/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>06/12/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>104245</amountOfSecuritiesAcquired>
            <paymentDate>06/12/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for MICHAEL MACLEAN</name>
                <address>
                    <ns2:street1>10578 Science Center Drive, Suite 125</ns2:street1>
                    <ns2:city>San Diego</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>92121</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>05/14/2024</saleDate>
            <amountOfSecuritiesSold>75000</amountOfSecuritiesSold>
            <grossProceeds>2121045.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for MICHAEL MACLEAN</name>
                <address>
                    <ns2:street1>10578 Science Center Drive, Suite 125</ns2:street1>
                    <ns2:city>San Diego</ns2:city>
                    <ns2:stateOrCountry>CA</ns2:stateOrCountry>
                    <ns2:zipCode>92121</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>03/13/2024</saleDate>
            <amountOfSecuritiesSold>40000</amountOfSecuritiesSold>
            <grossProceeds>980760.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>06/12/2024</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>05/23/2023</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Michael Maclean</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 4791}]
144
0001383731
XXXXXXXX
LIVE
0001599901
AVIDITY BIOSCIENCES INC
001-39321
10578 Science Center Drive, Suite 125
San Diego
CA
92121
8584017900
MICHAEL MACLEAN
Officer
COMMON
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
104245
3014765.40
95636748
06/12/2024
NASDAQ
Common
06/12/2024
Exercise of Stock Options
Issuer
N
104245
06/12/2024
Cash
N
10b5-1 Sales for MICHAEL MACLEAN
10578 Science Center Drive, Suite 125
San Diego
CA
92121
COMMON
05/14/2024
75000
2121045.00
10b5-1 Sales for MICHAEL MACLEAN
10578 Science Center Drive, Suite 125
San Diego
CA
92121
COMMON
03/13/2024
40000
980760.00
06/12/2024
05/23/2023
/s/ Michael Maclean