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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-01-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001776197</issuerCik>
        <issuerName>AKUMIN INC.</issuerName>
        <issuerTradingSymbol>AKU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001738045</rptOwnerCik>
            <rptOwnerName>SCW Capital Management, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001638046</rptOwnerCik>
            <rptOwnerName>SCW Capital, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001738855</rptOwnerCik>
            <rptOwnerName>SCW Capital QP, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001820813</rptOwnerCik>
            <rptOwnerName>SCW Single-Asset Partnership, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001823555</rptOwnerCik>
            <rptOwnerName>SCW Single-Asset Partnership QP, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001902856</rptOwnerCik>
            <rptOwnerName>Trinity Investment Group, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001902816</rptOwnerCik>
            <rptOwnerName>Cathey Robert N.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001056313</rptOwnerCik>
            <rptOwnerName>SMITH G STACY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001903982</rptOwnerCik>
            <rptOwnerName>Wagner John R.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3131 TURTLE CREEK BLVD., #302</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75219</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2022-01-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>75000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.66</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2020851</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footones</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2022-01-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>75000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.66</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4430203</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footones</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1903597</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footones</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F8"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3065257</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footones</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>60000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footones</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F10"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footones</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F11"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>33309</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footones</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F12"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents a cross-trade between SCW Capital, LP (&quot;SCW Capital&quot;) and SCW Single-Asset Partnership, LP (&quot;SCW Single-Asset Partnership&quot;), in which SCW Single-Asset Partnership disposed of and SCW Capital acquired common shares of Akumin Inc. (the &quot;Issuer&quot;). The reported transactions occurred simultaneously at no profit to the reporting persons and resulted in no change in the aggregate beneficial ownership of the reporting persons that may be exempt from Section 16 of the Securities Exchange Act of 1934, as amended (the &quot;Act&quot;), pursuant to Rule 16a-13 thereunder.</footnote>
        <footnote id="F2">This statement is jointly filed by and on behalf of each of SCW Capital, SCW Capital QP, LP (&quot;SCW Capital QP&quot;), SCW Single-Asset Partnership, SCW Single-Asset Partnership QP, LP (&quot;SCW Single-Asset Partnership QP&quot;), Trinity Investment Group, LLC (&quot;Trinity&quot;), SCW Capital Management, LP (&quot;SCW Capital Management&quot;), Robert N. Cathey, John R. Wagner, and G. Stacy Smith. SCW Capital, SCW Capital QP, SCW Single-Asset Partnership, SCW Single-Asset Partnership QP, Mr. Cathey, Mr. Wagner, and Mr. Smith are the direct beneficial owners of the securities covered by this statement.</footnote>
        <footnote id="F3">SCW Capital Management is the investment manager of, and may be deemed to beneficially own securities owned by, each of SCW Capital, SCW Capital QP, SCW Single-Asset Partnership, and SCW Single-Asset Partnership QP. Trinity is the general partner of, and may be deemed to beneficially own securities owned by, each of SCW Capital, SCW Capital QP, SCW Single-Asset Partnership, SCW Single-Asset Partnership QP, and SCW Capital Management. Mr. Cathey, Mr. Wagner, and Mr. Smith are the co-managers of, and may each be deemed to beneficially own securities owned by, Trinity.</footnote>
        <footnote id="F4">Each reporting person states that neither the filing of this statement nor anything herein shall be deemed an admission that such person is, for purposes of Section 16 of the Act or otherwise, the beneficial owner of any securities covered by this statement. Each reporting person disclaims beneficial ownership of the securities covered by this statement, except to the extent of the pecuniary interest of such person in such securities.</footnote>
        <footnote id="F5">Each reporting person may be deemed to be a member of a group with respect to the Issuer or securities of the Issuer for purposes of Section 13(d) or 13(g) of the Act. Each reporting person declares that neither the filing of this statement nor anything herein shall be construed as an admission that such person is, for the purposes of Section 13(d) or 13(g) of the Act or any other purpose, a member of a group with respect to the Issuer or securities of the Issuer.</footnote>
        <footnote id="F6">SCW Single-Asset Partnership, LP is the record and direct beneficial owner of these securities of the Issuer.</footnote>
        <footnote id="F7">SCW Capital, LP is the record and direct beneficial owner of these securities of the Issuer.</footnote>
        <footnote id="F8">SCW Capital QP, LP is the record and direct beneficial owner of these securities of the Issuer.</footnote>
        <footnote id="F9">SCW Single-Asset Partnership QP, LP is the record and direct beneficial owner of these securities of the Issuer.</footnote>
        <footnote id="F10">Robert N. Cathey is the record and direct beneficial owner of these securities of the Issuer.</footnote>
        <footnote id="F11">John R. Wagner is the record and direct beneficial owner of these securities of the Issuer.</footnote>
        <footnote id="F12">G. Stacy Smith is the record and direct beneficial owner of these securities of the Issuer.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>SCW CAPITAL MANAGEMENT, LP By: 	Trinity Investment Group, LLC Its: General Partner By:	/s/ John R. Wagner, Name: John R. Wagner, Title: Co-Managing Member</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SCW CAPITAL, LP By:  Trinity Investment Group, LLC Its: General Partner By: /s/ John R. Wagner, Name: John R. Wagner, Title: Co-Managing Member</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SCW CAPITAL QP, LP By: Trinity Investment Group, LLC Its: General Partner By: /s/ John R. Wagner, Name: John R. Wagner, Title: Co-Managing Member</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SCW SINGLE-ASSET PARTNERSHIP, LP By: Trinity Investment Group, LLC Its: General Partner By: /s/ John R. Wagner, Name: John R. Wagner, Title: Co-Managing Member</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>SCW SINGLE-ASSET PARTNERSHIP QP, LP By: Trinity Investment Group, LLC Its: General Partner By: /s/ John R. Wagner, Name: John R. Wagner, Title: Co-Managing Member</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>TRINITY INVESTMENT GROUP, LLC By: /s/ John R. Wagner, Name: John R. Wagner, Title: Co-Managing Member</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>ROBERT N. CATHEY, /s/ Robert N. Cathey</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>G. STACY SMITH, /s/ G. Stacy Smith</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>JOHN R. WAGNER, /s/ John R. Wagner</signatureName>
        <signatureDate>2022-01-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
