Exhibit 23.1

KPMG LLP

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Montréal (Québec) H3A 0A3

Tel. 514-840-2100

Fax. 514-840-2187

www.kpmg.ca

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the registration statements (No. 333-191383 and No. 333-227476) on Form S-8 and (No. 333-239538) on Form S-3 of Acasti Pharma Inc. of our report dated June 22, 2021, with respect to the consolidated balance sheets of Acasti Pharma Inc. as of March 31, 2021 and 2020, the related consolidated statements of loss and comprehensive loss, changes in shareholders’ equity and cash flows for the years ended March 31, 2021 and 2020, and the related notes.

Montréal, Canada

June 22, 2021

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