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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-11-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001716621</issuerCik>
        <issuerName>Ra Medical Systems, Inc.</issuerName>
        <issuerTradingSymbol>RMED</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001345539</rptOwnerCik>
            <rptOwnerName>McGuire Jonathan Will</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O RA MEDICAL SYSTEMS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2070 LAS PALMAS DRIVE</rptOwnerStreet2>
            <rptOwnerCity>CARLSBAD</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92011</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-11-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>104254</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110054</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reported shares were issued as a restricted stock award (&quot;RSA&quot;). 50% of the shares underlying the RSA shall vest and become non-forfeitable as follows:  1/3 of the number of shares will vest on November 20, 2021, and 1/6th of the number of shares will vest on each May 20 and November 20 thereafter, such that 50% of the RSA will be fully vested on November 20, 2023; provided, however, that if a vesting date would otherwise fall on a day when the national stock exchange upon which the shares are listed is not open for trading, vesting will occur on the first trading day thereafter. The remaining 50% of the shares underlying the RSA shall vest and become non-forfeitable upon certain performance milestones being met by November 20, 2021. Vesting in all instances is subject to the reporting person's continuous status as a Service Provider (as defined in the 2018 Equity Incentive Plan) through each vesting date.</footnote>
        <footnote id="F2">On November 16, 2020, the common stock of the company reverse-split 25-for-1, resulting in the reporting persons ownership being reduced by 139,200.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Daniel Horwood, as Attorney-in-Fact</signatureName>
        <signatureDate>2020-11-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
