Exhibit 23.1

KPMG LLP

PO Box 10426 777 Dunsmuir Street

Vancouver BC V7Y 1K3

Canada

Telephone (604) 691-3000

Fax (604) 691-3031

Consent of Independent Registered Public Accounting Firm

The Board of Directors of Methanex Corporation

We consent to the use of:

•our report dated March 10, 2023 on the consolidated financial statements of Methanex Corporation(the “Entity”) which comprise the consolidated statements of financial position as of December 31, 2022 and December 31, 2021, the related consolidated statements of income, comprehensive income, changes in equity and cash flows for each of the years in the two-year period ended December 31, 2022, and the related notes, and

•our report dated March 10, 2023 on the effectiveness of the Entity’s internal control over financial reporting as of December 31, 2022

each of which is included in the Annual Report on Form 40-F of the Entity for the fiscal year ended December 31, 2022.

We also consent to the incorporation by reference of such reports in the Registration Statements (No. 333-112624, No. 333-141833, No. 333-194850, and No. 33-217591) on Form S-8 of the Entity.

/s/ KPMG LLP

Chartered Professional Accountants

March 10, 2023

Vancouver, Canada

KPMG LLP, an Ontario limited liability partnership and member firm of the KPMG global

organization of independent member firms affiliated with KPMG International Limited, a private

English company limited by guarantee. KPMG Canada provides services to KPMG LLP.

Document classification. Confidential.