Osisko Development Corp. — Capital/Financing Update 2026

Jan 28, 2026

pwc

January 27, 2026

British Columbia Securities Commission
Alberta Securities Commission
Financial and Consumer Affairs Authority of Saskatchewan
Manitoba Securities Commission
Ontario Securities Commission
Autorité des marchés financiers (Québec)
Financial and Consumer Services Commission (New Brunswick)
Nova Scotia Securities Commission
Office of the Superintendent of Securities Service Newfoundland and Labrador
Financial and Consumer Services Division (Prince Edward Island)
Office of the Superintendent of Securities (Northwest Territories)
Office of the Yukon Superintendent of Securities
Office of the Superintendent of Securities Nunavut

We refer to the prospectus supplement dated January 27, 2026 to the short form base shelf prospectus dated December 23, 2025 of Osisko Development Corporation (the Corporation) relating to the distribution of common shares.

We consent to being named in and to the use, through incorporation by reference, in the above-mentioned prospectus supplement of our report dated March 28, 2025 to the Board of Directors and Shareholders of the Corporation on the following:

• consolidated statements of financial position as of December 31, 2024 and 2023;
• consolidated statements of loss, of comprehensive loss, of cash flows and of changes in equity for the years then ended; and
• the related notes.

PricewaterhouseCoopers LLP
1250 René-Lévesque Boulevard West, Suite 2500
Montréal, Quebec, Canada H3B 4Y1
T.: +1 514 205 5000, F.: +1 514 876 1502,
Fax to mail: ca_montreal_main_fax@pwc.com

PwC' refers to PricewaterhouseCoopers LLP, an Ontario limited liability partnership.

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We report that we have read the prospectus supplement and all information specifically incorporated by reference therein and have no reason to believe that there are any misrepresentations in the information contained therein that is derived from the consolidated financial statements on which we have reported, or that are within our knowledge as a result of our audit of such consolidated financial statements. We have complied with Canadian generally accepted standards for an auditor's consent to the use of a report of the auditor included in an offering document, which does not constitute an audit or review of the prospectus as these terms are described in the CPA Canada Handbook – Assurance.

/s/PricewaterhouseCoopers LLP

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