<SEC-DOCUMENT>0001209191-21-034694.txt : 20210520
<SEC-HEADER>0001209191-21-034694.hdr.sgml : 20210520
<ACCEPTANCE-DATETIME>20210520202811
ACCESSION NUMBER:		0001209191-21-034694
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210517
FILED AS OF DATE:		20210520
DATE AS OF CHANGE:		20210520

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Reijn Barend
		CENTRAL INDEX KEY:			0001789124

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34198
		FILM NUMBER:		21946284

	MAIL ADDRESS:	
		STREET 1:		100 ENTERPRISE WAY
		STREET 2:		SUITE B 101
		CITY:			SCOTTS VALLEY
		STATE:			CA
		ZIP:			95066

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SunOpta Inc.
		CENTRAL INDEX KEY:			0000351834
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-FARM PRODUCT RAW MATERIALS [5150]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			Z4
		FISCAL YEAR END:			0101

	BUSINESS ADDRESS:	
		STREET 1:		2233 ARGENTIA ROAD
		STREET 2:		SUITE 401
		CITY:			MISSISSAUGA
		STATE:			A6
		ZIP:			L5N 2X7
		BUSINESS PHONE:		(905) 455-1990

	MAIL ADDRESS:	
		STREET 1:		2233 ARGENTIA ROAD
		STREET 2:		SUITE 401
		CITY:			MISSISSAUGA
		STATE:			A6
		ZIP:			L5N 2X7

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SUNOPTA INC
		DATE OF NAME CHANGE:	20031107

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	STAKE TECHNOLOGY LTD
		DATE OF NAME CHANGE:	19940901
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-05-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000351834</issuerCik>
        <issuerName>SunOpta Inc.</issuerName>
        <issuerTradingSymbol>STKL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001789124</rptOwnerCik>
            <rptOwnerName>Reijn Barend</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 ENTERPRISE WAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE B 101</rptOwnerStreet2>
            <rptOwnerCity>SCOTTS VALLEY</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95066</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>General Manager of CPG Fruit</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2021-05-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9711</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.495</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>82463</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2021-05-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8888</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.6549</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>73575</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2021-05-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8886</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.3591</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>64689</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents the number of shares sold by the reporting person solely to cover the tax withholding obligations in connection with the settlement of the PSUs that vested on April 22, 2021, as previously reported.</footnote>
        <footnote id="F2">The transaction was executed in multiple trades at prices ranging from $12.35 to $12.62. The price reported reflects the average sale price. The reporting person undertakes to provide the SEC staff, the issuer or a security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F3">The transaction was executed in multiple trades at prices ranging from $12.52 to $12.79. The price reported reflects the average sale price. The reporting person undertakes to provide the SEC staff, the issuer or a security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F4">The transaction was executed in multiple trades at prices ranging from $12.11 to $12.67. The price reported reflects the average sale price. The reporting person undertakes to provide the SEC staff, the issuer or a security holder of the issuer, upon request, full information regarding the number of shares sold at each separate price.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jill Barnett, attorney-in-fact</signatureName>
        <signatureDate>2021-05-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
