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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-08-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001083522</issuerCik>
        <issuerName>JONES SODA CO</issuerName>
        <issuerTradingSymbol>JSDA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001710138</rptOwnerCik>
            <rptOwnerName>SOL Global Investments Corp.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 KING STREET WEST</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 5600</rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5X 1C9</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2022-08-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1500000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.26</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14515035</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>SOL Verano Blocker 1 LLC</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>281345</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person's sale of the Issuer's common stock disclosed above was matchable under Section 16(b) of the Securities and Exchange Act of 1934, with purchases of 79,000 common shares of the Issuer between March 18, 2022, and March 25, 2022, at prices ranging from $0.552 to $0.56, and purchases on April 22, 2022, at prices ranging from $0.319 to $0.35.  No short-swing profits were realized  by the Reporting Person in connection with the sale on August 16, 2022.</footnote>
        <footnote id="F2">The reported sale price was converted from Canadian sale price of C$0.34 using an exchange rate of C$1.2867 = US$1.00.</footnote>
        <footnote id="F3">SOL Verano Blocker 1 LLC is a wholly-owned subsidiary of the reporting person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Kevin Taylor</signatureName>
        <signatureDate>2022-08-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
