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        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001829259</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001562088</issuerCik>
            <issuerName>DUOLINGO INC</issuerName>
            <secFileNumber>001-40653</secFileNumber>
            <issuerAddress>
                <ns2:street1>5900 Penn Avenue </ns2:street1>
                <ns2:city>Pittsburgh</ns2:city>
                <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                <ns2:zipCode>15206</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>4125676602</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>LUIS VON AHN ARELLANO</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>24000</noOfUnitsSold>
            <aggregateMarketValue>5293920.00</aggregateMarketValue>
            <noOfUnitsOutstanding>36680751</noOfUnitsOutstanding>
            <approxSaleDate>04/01/2024</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>04/01/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>24000</amountOfSecuritiesAcquired>
            <paymentDate>04/01/2024</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/11/2024</saleDate>
            <amountOfSecuritiesSold>22023</amountOfSecuritiesSold>
            <grossProceeds>4850882.88</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/08/2024</saleDate>
            <amountOfSecuritiesSold>18004</amountOfSecuritiesSold>
            <grossProceeds>3879084.23</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>03/08/2024</saleDate>
            <amountOfSecuritiesSold>12153</amountOfSecuritiesSold>
            <grossProceeds>2618351.70</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/07/2024</saleDate>
            <amountOfSecuritiesSold>100</amountOfSecuritiesSold>
            <grossProceeds>21500.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>03/07/2024</saleDate>
            <amountOfSecuritiesSold>100</amountOfSecuritiesSold>
            <grossProceeds>21500.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/06/2024</saleDate>
            <amountOfSecuritiesSold>2273</amountOfSecuritiesSold>
            <grossProceeds>490082.21</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>03/06/2024</saleDate>
            <amountOfSecuritiesSold>2373</amountOfSecuritiesSold>
            <grossProceeds>511642.06</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/05/2024</saleDate>
            <amountOfSecuritiesSold>13600</amountOfSecuritiesSold>
            <grossProceeds>2833362.48</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO</name>
                <address>
                    <ns2:street1>5900 Penn Avenue </ns2:street1>
                    <ns2:city>Pittsburgh</ns2:city>
                    <ns2:stateOrCountry>PA</ns2:stateOrCountry>
                    <ns2:zipCode>15206</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <saleDate>03/05/2024</saleDate>
            <amountOfSecuritiesSold>7374</amountOfSecuritiesSold>
            <grossProceeds>1534760.58</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>The securities to be sold were and will be received upon the exercise of stock options over the next three months.
</remarks>
        <noticeSignature>
            <noticeDate>04/01/2024</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>11/30/2023</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Luis Von Ahn</signature>
        </noticeSignature>
    </formData>
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144
0001829259
XXXXXXXX
LIVE
0001562088
DUOLINGO INC
001-40653
5900 Penn Avenue
Pittsburgh
PA
15206
4125676602
LUIS VON AHN ARELLANO
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
24000
5293920.00
36680751
04/01/2024
NASDAQ
Common
04/01/2024
Exercise of Stock Options
Issuer
N
24000
04/01/2024
Cash
N
10b5-1 Sales for LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
Common
03/11/2024
22023
4850882.88
10b5-1 Sales for LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
Common
03/08/2024
18004
3879084.23
10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
COMMON
03/08/2024
12153
2618351.70
10b5-1 Sales for LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
Common
03/07/2024
100
21500.00
10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
COMMON
03/07/2024
100
21500.00
10b5-1 Sales for LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
Common
03/06/2024
2273
490082.21
10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
COMMON
03/06/2024
2373
511642.06
10b5-1 Sales for LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
Common
03/05/2024
13600
2833362.48
10b5-1 Sales for LUIS VON AHN FOUNDATIONC/O LUIS VON AHN ARELLANO
5900 Penn Avenue
Pittsburgh
PA
15206
COMMON
03/05/2024
7374
1534760.58
The securities to be sold were and will be received upon the exercise of stock options over the next three months.
04/01/2024
11/30/2023
/s/ Luis Von Ahn