Osisko Development Corp. — Proxy Solicitation & Information Statement 2023

Apr 11, 2023

NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

NOTICE IS HEREBY GIVEN that the annual meeting (the "Meeting") of the shareholders of OSISKO DEVELOPMENT CORP. (the "Corporation") will be held on May 11, 2023 at 2:00 p.m. (Eastern Daylight Time). The Meeting will be held at the Montreal offices of Norton Rose Fulbright Canada LLP located at 1, Place Ville Marie, Suite 2500, Montreal, QC, H3B 1R1, for the following purposes:

1. To receive the audited financial statements of the Corporation for the year ended December 31, 2022, together with the report of the auditor thereon;
2. To elect the directors of the Corporation for the ensuing year;
3. To appoint PricewaterhouseCoopers LLP/s.r.l./s.e.n.c.r.l., a partnership of Chartered Professional Accountants, as the Corporation's independent auditor for the fiscal year 2023 and to authorize the directors to fix its remuneration;
4. To consider and, if deemed advisable, to pass, with or without amendments, an ordinary resolution to approve the Corporation's existing Stock Option Plan (as more particularly described on page 20 and following of the management information circular that accompanies this Notice of Meeting (the "Circular")); and
5. To transact such further or other business as may properly come before the meeting or any postponement(s) or adjournment(s) thereof.

IMPORTANT

You are entitled to vote at the Meeting and any postponement or adjournment thereof if you owned Common Shares at the close of business on March 31, 2023. For information on how you may vote, please refer to Part 1 of this Circular.

To be effective, the form of proxy or voting instruction form (the "VIF"), as applicable, must be completed and returned in accordance with the instructions provided in the Circular no later than 2:00 p.m. (Eastern Daylight Time) on May 9, 2023 or, in the event the Meeting is adjourned, 48 hours (other than a Saturday, Sunday or holiday) prior to the time to which the Meeting is adjourned.

NOTICE AND ACCESS

The Corporation has decided to use the Notice and Access rules adopted by the Canadian Securities Administrators to reduce the volume of paper with respect to materials distributed for the purpose of the Meeting. Instead of receiving the Circular, shareholders will receive a Notice of Meeting with instructions on how to access the remaining Meeting materials online together with the form of proxy or VIF, as the case may be. The Circular and other relevant materials are available on SEDAR (sedar.com), on the U.S. Securities and Exchange Commission ("SEC") website (www.sec.gov) through EDGAR, and under the "Investors" section of the Corporation's corporate website (https://osiskodev.com/investors/). Shareholders are advised to review the Meeting materials prior to voting. If you have questions about Notice and Access, you can call our transfer agent, TSX Trust Company toll-free at 1-866-600-5869 or write an email to tsxtis@tmx.com.

Any shareholder who wishes to receive a paper copy of the Meeting materials may, at no cost, request such printed copies by emailing the request to tsxtis@tmx.com or calling 1-866-600-5869 toll-free and entering the twelve (12) digit control number provided on the form of proxy or VIF and following the instructions provided. If a paper copy of the Meeting materials is required, we recommend sending the request as soon as possible, and ideally before April 25, 2023, in order to allow for sufficient time to receive and review said Meeting materials and return the form of proxy or VIF in the prescribed time. Note that if

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you request a paper copy of the Circular, you will not receive a new form of proxy or VIF. You should keep the original form sent to you in order to vote.

Your participation is important to us and we encourage you to exercise your vote by completing the proxy form prior to the Meeting, even if you expect to attend. In the event you cannot participate at the Meeting, we urge you to express your support by voting, using your proxy in advance of the meeting, on the various proposals that will be putting forward at the Meeting, which are further described in the Circular.

Montréal, Québec, March 31, 2023.

By Order of the Board of Directors,

Sean Roosen
Chair of the Board of Directors and
Chief Executive Officer

2023 Management Information Circular
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