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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2020-11-18</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001497504</issuerCik>
        <issuerName>PLx Pharma Inc.</issuerName>
        <issuerTradingSymbol>PLXP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001674751</rptOwnerCik>
            <rptOwnerName>Level One Partners, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>210 RIDGE MCINTIRE ROAD, SUITE 350</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTESVILLE</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22903</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001804350</rptOwnerCik>
            <rptOwnerName>Hardie Robert D.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>210 RIDGE MCINTIRE ROAD, SUITE 350</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTESVILLE</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22903</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001804348</rptOwnerCik>
            <rptOwnerName>Hardie Molly G.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>210 RIDGE MCINTIRE ROAD, SUITE 350</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTESVILLE</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22903</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $0.001 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1320306</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $0.001 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>875000</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Warrants (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.31</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2020-11-18</value>
            </exerciseDate>
            <expirationDate>
                <value>2025-11-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1452337</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Level One Partners, LLC (the &quot;Reporting Person&quot;) is owned by Robert D. Hardie (&quot;Mr. Hardie&quot;) and Molly G. Hardie (&quot;Ms. Hardie&quot;), who are married. Mr. Hardie is the manager of the Reporting Person and also holds shares of PLx Pharma Inc. (the &quot;Company&quot;) individually.</footnote>
        <footnote id="F2">As of the date of this report, the Reporting Person holds 1,320,306 shares of Common Stock, $.001 par value per share (the &quot;Common Stock&quot;) of the Company, and Mr. Hardie holds 875,000 shares of Common Stock of the Company.  Pursuant to 17 CFR Section 240.16a-1(a)(2), Ms. Hardie's beneficial ownership is limited to her pecuniary interest, if any, in such securities.</footnote>
        <footnote id="F3">As of the date of this report, the Reporting Person holds warrants to purchase 1,452,337 shares of Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Robert D. Hardie, Manager of Level One Partners, LLC</signatureName>
        <signatureDate>2021-03-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Robert D. Hardie</signatureName>
        <signatureDate>2021-03-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Molly G. Hardie</signatureName>
        <signatureDate>2021-03-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
