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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-01-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001401040</issuerCik>
        <issuerName>DiaMedica Therapeutics Inc.</issuerName>
        <issuerTradingSymbol>DMAC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001341125</rptOwnerCik>
            <rptOwnerName>Kuntz Richard</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>301 CARLSON PARKWAY, SUITE 210</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55305</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Voting Common Shares, no par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2025-01-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9925</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.34</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24210</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares are issuable upon vesting and settlement of a restricted stock unit award granted under the DiaMedica Therapeutics Inc. Amended and Restated 2019 Omnibus Incentive Plan in lieu of cash retainer fees in the aggregate amount of $53,000.  The restricted stock unit award will vest in four nearly equal installments on each of March 31, 2025, June 30, 2025, September 30, 2025 and December 31, 2025.</footnote>
        <footnote id="F2">Includes 9,925 shares issuable on vesting of a restricted stock unit award granted under the DiaMedica Therapeutics Inc. Amended and Restated 2019 Omnibus Incentive Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Amy E. Culbert, attorney-in-fact</signatureName>
        <signatureDate>2025-01-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
