Osisko Development Corp. — Declaration of Voting Results & Voting Rights Announcements 2021

Mar 19, 2021

TSX TRUST COMPANY

VIA ELECTRONIC TRANSMISSION

March 19, 2021

TO ALL APPLICABLE EXCHANGES AND COMMISSIONS:

RE: OSISKO DEVELOPMENT CORP. Confirmation of Notice of Record and Meeting Dates

We are pleased to confirm that Notice of Record and Meeting Dates was sent to The Canadian Depository for Securities.

We advise the following with respect to the upcoming Annual Meeting of Security Holders for the subject issuer:

1. ISIN: CA68828E1060 CA68828E2050 CA68828E5020
2. Date Fixed for the Meeting: May 12, 2021
3. Record Date for Notice: March 22, 2021
4. Record Date for Voting: March 22, 2021
5. Beneficial Ownership Determination Date: March 22, 2021
6. Classes or Series of Securities that entitle the holder to receive Notice of the Meeting: COMMON RESTRICTED RESTRICTED
7. Classes or Series of Securities that entitle the holder to vote at the meeting: COMMON RESTRICTED RESTRICTED
8. Business to be conducted at the meeting: Annual
9. Notice-and-Access: Registered Shareholders: NO Beneficial Holders: NO Stratification Level: Not Applicable
10. Reporting issuer is sending proxy-related materials directly to Non-Objecting Beneficial Owners: YES
11. Issuer paying for delivery to Objecting Beneficial Owners: YES

Yours truly, TSX Trust Company

" Julien Lavallière " Senior Relationship Manager Julien.Lavalliere@tmx.com

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