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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2021-02-03</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001785345</issuerCik>
        <issuerName>Landos Biopharma, Inc.</issuerName>
        <issuerTradingSymbol>LABP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001843646</rptOwnerCik>
            <rptOwnerName>Colombel Jean-Frederic</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LANDOS BIOPHARMA, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1800 KRAFT DRIVE, SUITE 216</rptOwnerStreet2>
            <rptOwnerCity>BLACKSBURG</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>24060</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <footnotes></footnotes>

    <remarks>No Table I or Table II securities beneficially owned.

Exhibit List - Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Eric W. Blanchard, Attorney-in-Fact</signatureName>
        <signatureDate>2021-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
