Osisko Development Corp. — Capital/Financing Update 2026

Jan 28, 2026

Bennett Jones

Bennett Jones LLP
3400 One First Canadian Place, PO Box 130
Toronto, Ontario, Canada M5X 1A4
Tel: 416.863.1200 Fax: 416.863.1716

January 27, 2026

VIA SEDAR+

Autorité des marchés financiers, as Principal
British Columbia Securities Commission
Alberta Securities Commission
Financial and Consumer Affairs Authority of Saskatchewan
The Manitoba Securities Commission
Ontario Securities Commission
Financial and Consumer Services Commission, New Brunswick
Nova Scotia Securities Commission
Superintendent of Securities, Prince Edward Island
Superintendent of Securities, Newfoundland and Labrador
Northwest Territories Superintendent of Securities
Government of Nunavut – Superintendent of Securities
Yukon Superintendent of Securities

Dear Sirs/Mesdames:

Re: Osisko Development Corp. – Prospectus Supplement dated January 27, 2026 to the Short Form Base Shelf Prospects dated December 23, 2025

We refer to the prospectus supplement dated January 22, 2026 ("Prospectus Supplement") to the short form base shelf prospectus dated December 23, 2025 of Osisko Development Corp. (the "Corporation"), which Prospectus Supplement relates to the offering of units of the Corporation in all of the provinces and territories of Canada.

We hereby consent to the references to our firm's name on page (iii) and under the headings "Eligibility for Investment", "Enforcement of Civil Liabilities", and "Legal Matters" of the Prospectus Supplement and to the use of our opinion under the heading "Eligibility for Investment" in the Prospectus Supplement, which opinion is dated as of the date of the Prospectus Supplement.

We confirm that we have read the Prospectus Supplement and that we have no reason to believe that there are any misrepresentations in the information contained therein that are derived from our opinion referred to therein or that are within our knowledge as a result of the services we have performed in connection with such opinion.

Yours truly,

(signed) "Bennett Jones LLP"

Bennett Jones LLP

www.bennettjones.com