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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2017-06-19</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000880242</issuerCik>
        <issuerName>BIOLARGO, INC.</issuerName>
        <issuerTradingSymbol>BLGO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001663146</rptOwnerCik>
            <rptOwnerName>STROMMEN JACK B.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7108 31ST AVENUE NORTH</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55427</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock Warrants (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.4000</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2015-08-26</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-06-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1400000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock Warrants (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.4500</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2015-10-08</value>
            </exerciseDate>
            <expirationDate>
                <value>2026-06-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1857143</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Convertible Promissory Notes due 2018</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.2500</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2015-08-26</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1400000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Convertible Promissory Notes due 2018</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.3500</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2015-10-08</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-06-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1857143</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The Common Stock Warrants described are comprised of two separate Warrant grants, made on August 26, 2015 and September 9, 2015, respectively. Each such Common Stock Warrant includes identical terms and was immediately exercisable upon grant.</footnote>
        <footnote id="F2">The Convertible Promissory Notes described are comprised of two Convertible Promissory Notes, issued on August 26, 2015 and September 9, 2015, respectively. Each such Convertible Promissory Note includes identical terms and was immediately convertible upon issuance.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jack B. Strommen</signatureName>
        <signatureDate>2017-06-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
