<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-07-22</periodOfReport>

    <issuer>
        <issuerCik>0000946486</issuerCik>
        <issuerName>WINDTREE THERAPEUTICS INC /DE/</issuerName>
        <issuerTradingSymbol>WINT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001624401</rptOwnerCik>
            <rptOwnerName>Simonson Steven</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2600 KELLY ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>WARRINGTON</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>18976</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP, Chief Medical Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series C Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-07-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>13</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3471</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrants (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.11</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-07-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2674</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2674</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2674</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On July 22, 2024, the Reporting Person acquired 13 shares of the Issuer's Series C Convertible Preferred Stock, $0.001 par value (&quot;Series C Preferred Stock&quot;), in a private placement by the Issuer pursuant to the terms of a Securities Purchase Agreement dated as of July 18, 2024 (the &quot;Purchase Agreement&quot;). The shares of Series C Preferred Stock have the rights and preferences set forth on the certificate of designations of Series C Preferred Stock filed with the Secretary of State for the State of Delaware on July 19, 2024. The Series C Preferred Stock has a stated value of $1,000 per share and currently has a conversion price of $3.74 per share. The Series C Preferred Stock has no expiration date.</footnote>
        <footnote id="F2">Pursuant to the Purchase Agreement, the Reporting Person acquired 2,674 warrants to purchase 2,674 shares of the Issuer's common stock, $0.001 par value per share (&quot;Warrants&quot;). The Warrants have an exercise price of $4.11 per share, subject to customary adjustments, and will become exercisable on the six month and one day anniversary of the issuance date (the &quot;Initial Exercisability Date&quot;), and expire on the fifth (5th) anniversary of the Initial Exercisability Date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jamie McAndrew, as Attorney-in-Fact</signatureName>
        <signatureDate>2024-07-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
