RNGTD / Osisko Development Corp - SEC-Einreichungen, Jahresbericht, Proxy Statement

Osisko Development Corp
US ˙ OTC
DIESES SYMBOL IST NICHT MEHR AKTIV

Basisstatistiken
LEI 984500A8CC57F67DJ124
CIK 1431852
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Osisko Development Corp
SEC Filings (Chronological Order)
Auf dieser Seite finden Sie eine vollständige, chronologische Liste der SEC-Einreichungen, mit Ausnahme der Eigentumseinreichungen, die wir an anderer Stelle bereitstellen.
June 2, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execu

June 2, 2026 EX-99.1

FORM 51-102F3 Material Change Report

Exhibit 99.1 FORM 51-102F3 Material Change Report Item 1: Name and Address of Company Osisko Development Corp. (the “Company”) 1100 Av. Des Canadiens-de-Montréal, Suite 300 Montréal, Québec, H3B 2S2, Canada Item 2: Date of Material Change May 21, 2026 Item 3: News Release News releases dated May 21, 2026, May 26, 2026 and June 1, 2026, were filed on the System of Electronic Data Analysis and Retri

June 2, 2026 EX-99.1

Osisko Development Announces Nomination of Keith McKay to the Board of Directors and Proposes Name Change to Osisko Gold Group Inc. at Upcoming Annual and Special Meeting of Shareholders

EXHIBIT 99.1 Osisko Development Announces Nomination of Keith McKay to the Board of Directors and Proposes Name Change to Osisko Gold Group Inc. at Upcoming Annual and Special Meeting of Shareholders MONTREAL, June 02, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces its upcoming annual and special meeting (the "Meeting") of

June 2, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (

June 1, 2026 EX-99.1

Osisko Development Announces Closings of Additional US$75 Million Aggregate Principal Amount of 4.125% Convertible Senior Notes Bringing Total Offering to US$300 Million

EXHIBIT 99.1 Osisko Development Announces Closings of Additional US$75 Million Aggregate Principal Amount of 4.125% Convertible Senior Notes Bringing Total Offering to US$300 Million Additional Notes represent full exercise of Initial Purchasers’ Option from previously announced Offering and closing of non-brokered private placement notes with Double Zero Capital Opportunistic capital raise with n

June 1, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (

May 28, 2026 EX-99.1

Osisko Development to Complete Fourth Deferred Payment Installment in Connection with the Tintic Acquisition

EXHIBIT 99.1 Osisko Development to Complete Fourth Deferred Payment Installment in Connection with the Tintic Acquisition MONTREAL, May 28, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces that, in accordance with the terms of the Company's previously-completed acquisition in May 2022 of a 100% ownership interest in the Tinti

May 28, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 27, 2026 EX-2.01.SCH

EX-2.01.SCH

It represents the information pertaining to the San Antonio Project. San Antonio Project [Member] San Antonio Project (Sapuchi) It represents the information pertaining to the Cariboo Gold Project. Cariboo Gold Project It represents the information pertaining to the Tintic Project. Tintic Project [Member] Tintic Project (Trixie) CANADA MEXICO UNITED STATES It represents the information pertaining

May 27, 2026 EX-2.01

Extractive Sector Transparency Measures Act - Annual Report

Exhibit 2.01 Extractive Sector Transparency Measures Act - Annual Report Reporting Entity Name Osisko Development Corp. Reporting Year From 1/1/2025 To: 12/31/2025 Date submitted 5/22/2026 Reporting Entity ESTMA Identification Number E335878  Original Submission  Amended Report Other Subsidiaries Included (optional field) Not Consolidated Not Substituted Attestation by Reporting Entity In accordan

May 27, 2026 SD

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report OSISKO DEVELOPMENT CORP. (Exact name of registrant as specified in its charter)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report OSISKO DEVELOPMENT CORP. (Exact name of registrant as specified in its charter) Canada 001 41369 (State or other jurisdiction of incorporation) (Commission file number) 1100 Ave. des Canadiens-de-Montréal, Montréal, Quebec, Canada H3B 2S2 (Address of principal executive offices) (Zip code)

May 26, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 26, 2026 EX-99.1

OSISKO DEVELOPMENT ANNOUNCES CLOSING OF US$225.0 MILLION AGGREGATE PRINCIPAL AMOUNT OF 4.125% CONVERTIBLE SENIOR NOTES OFFERING

Exhibit 99.1 OSISKO DEVELOPMENT ANNOUNCES CLOSING OF US$225.0 MILLION AGGREGATE PRINCIPAL AMOUNT OF 4.125% CONVERTIBLE SENIOR NOTES OFFERING 🞂 Opportunistic capital raise with net proceeds expected to be used for the development of the Cariboo Gold Project and general corporate purposes 🞂 A portion of net proceeds expected to be used to purchase cash-settled capped calls to offset potential econ

May 26, 2026 EX-99.2

OSISKO DEVELOPMENT CORP. U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, as Trustee Dated as of May 26, 2026 4.125% Convertible Senior Notes due 2031 TABLE OF CONTENTS

Exhibit 99.2 OSISKO DEVELOPMENT CORP. AND U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, as Trustee INDENTURE Dated as of May 26, 2026 4.125% Convertible Senior Notes due 2031 TABLE OF CONTENTS Page Article 1 Definitions 1 Section 1.01. Definitions 1 Section 1.02. References to Interest 15 Article 2 Issue, Description, Execution, Registration and Exchange of Notes 16 Section 2.01. Designation and

May 26, 2026 EX-99.3

[Signature page to follow]

Exhibit 99.3 [Dealer Name and Address] [], 2026 Osisko Development Corp. [] [] [] Attention: [] [] Re: [Base][Additional][Affiliate Notes] Call Option Transaction The purpose of this letter agreement (this “Confirmation”) is to confirm the terms and conditions of the call option transaction entered into between [Dealer Name] (“Dealer”) and Osisko Development Corp. (“Counterparty”) as of the Trade

May 21, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 21, 2026 EX-99.1

Osisko Development Announces Proposed Offering of US$275.0 Million Aggregate Principal Amount of Convertible Senior Notes

EXHIBIT 99.1 Osisko Development Announces Proposed Offering of US$275.0 Million Aggregate Principal Amount of Convertible Senior Notes Opportunistic capital raise with net proceeds expected to be used for the development of the Cariboo Gold Project and general corporate purposes A portion of net proceeds expected to be used to purchase cash-settled capped calls to offset potential economic dilutio

May 21, 2026 EX-99.2

Osisko Development Announces Pricing of US$275.0 Million Aggregate Principal Amount of 4.125% Convertible Senior Notes Offering (25.0% Conversion Premium)

EXHIBIT 99.2 Osisko Development Announces Pricing of US$275.0 Million Aggregate Principal Amount of 4.125% Convertible Senior Notes Offering (25.0% Conversion Premium) Opportunistic capital raise with net proceeds expected to be used for the development of the Cariboo Gold Project and general corporate purposes A portion of net proceeds expected to be used to purchase cash-settled capped calls to

May 20, 2026 EX-99.1

Notice of Annual and Special Meeting of Shareholders and Management Information Circular May 11, 2026

Exhibit 99.1 Notice of Annual and Special Meeting of Shareholders and Management Information Circular May 11, 2026 Our annual and special meeting of shareholders will be held on June 23, 2026, at 1:30 p.m. (Eastern Time) at First Canadian Place, 100 King St W, Suite 3400, Toronto, Ontario, M5X 1A4. Shareholders may exercise their rights by attending the meeting or completing a form of proxy. If yo

May 20, 2026 EX-99.4

Notice-and-Access The Canadian securities regulators have adopted rules which permit the use of notice-and-access for proxy solicitation instead of the traditional physical delivery of materials. This new process provides the option to post meeting r

Exhibit 99.4 Notice-and-Access The Canadian securities regulators have adopted rules which permit the use of notice-and-access for proxy solicitation instead of the traditional physical delivery of materials. This new process provides the option to post meeting related materials including management information circulars, as well as annual financial statements and management’s discussion and analy

May 20, 2026 EX-99.3

Proxy Voting – Guidelines and Conditions 1. THIS PROXY IS SOLICITED BY OR ON BEHALF OF THE MANAGEMENT OF THE CORPORATION. 2. THIS PROXY SHOULD BE READ IN CONJUNCTION WITH THE MEETING MATERIALS PRIOR TO VOTING. 3. If you appoint the Management Nominee

Exhibit 99.3 Proxy Voting – Guidelines and Conditions 1. THIS PROXY IS SOLICITED BY OR ON BEHALF OF THE MANAGEMENT OF THE CORPORATION. 2. THIS PROXY SHOULD BE READ IN CONJUNCTION WITH THE MEETING MATERIALS PRIOR TO VOTING. 3. If you appoint the Management Nominees indicated on the reverse to vote on your behalf, they must also vote in accordance with your instructions or, if no instructions are gi

May 20, 2026 EX-99.6

Osisko Development Corp. Annual Report prepared in accordance with the Fighting Against Forced Labour and Child Labour in Supply Chains Act For the Financial Year Ended December 31, 2025

Exhibit 99.6 Osisko Development Corp. Annual Report prepared in accordance with the Fighting Against Forced Labour and Child Labour in Supply Chains Act For the Financial Year Ended December 31, 2025 1.             Introduction In this annual report (“Report”) made in accordance with the Fighting Against Forced Labour and Child Labour in Supply Chains Act, S.C. 2023, c.-9 (“Act”), references to “O

May 20, 2026 EX-99.5

OSISKO DEVELOPMENT CORP. (the “Corporation”) CERTIFICATE OF ABRIDGEMENT

Exhibit 99.5 OSISKO DEVELOPMENT CORP. (the “Corporation”) CERTIFICATE OF ABRIDGEMENT TO: Alberta Securities Commission British Columbia Securities Commission Financial and Consumer Affairs Authority of Saskatchewan Manitoba Securities Commission Ontario Securities Commission Autorité des marchés financiers Nova Scotia Securities Commission Financial and Consumer Services Commission (New Brunswick)

May 20, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execut

May 20, 2026 EX-99.2

NOTICE OF ANNUAL AND SPECIAL MEETING OF SHAREHOLDERS

Exhibit 99.2 NOTICE OF ANNUAL AND SPECIAL MEETING OF SHAREHOLDERS NOTICE IS HEREBY GIVEN that the annual and special meeting (the “Meeting”) of the shareholders of Osisko Development Corp. (the “Corporation”) will be held on June 23, 2026, at 1:30 p.m. (Eastern Time). The Meeting will be held at First Canadian Place, 100 King St W, Suite 3400, Toronto, Ontario, M5X 1A4, for the following purposes:

May 19, 2026 EX-99.1

Osisko Development Appoints Vice President, Sustainable Development

EXHIBIT 99.1 Osisko Development Appoints Vice President, Sustainable Development MONTREAL, May 19, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce the appointment of Mr. Greg Perrins as Vice President, Sustainable Development, effective May 18, 2026. "We are pleased to welcome Greg to the Osisko Development team

May 19, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 12, 2026 EX-99.1

OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three months ended March 31, 2026 and 2025

Exhibit 99.1 OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three months ended March 31, 2026 and 2025 Osisko Development Corp. Consolidated Statements of Financial Position As at March 31, 2026 and December 31 2025 (Unaudited) (Tabular amounts expressed in thousands of Canadian dollars) March 31, December 31, 2026

May 12, 2026 EX-99.1

Osisko Development Reports First Quarter 2026 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise)

EXHIBIT 99.1 Osisko Development Reports First Quarter 2026 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise) HIGHLIGHTS Q1 2026 (at March 31, 2026) Financial: ~$594.3 million in cash and cash equivalents; sold 270 ounces of gold from small-scale mining activities at the Tintic Project; received ~$36.5 million in proceeds from warrant exercises Financing: Compl

May 12, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execut

May 12, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 12, 2026 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Sean Roosen, Chair of the Board and Chief Executive Officer of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended March 31, 2026. 2. No misrepr

May 12, 2026 EX-99.2

OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three months ended March 31, 2026

Table of Contents Exhibit 99.2 OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three months ended March 31, 2026 The following management’s discussion and analysis ("MD&A") of the operations and financial position of Osisko Development Corp. and its subsidiaries ("Osisko Development" or the "Company") for the three months ended March 31, 2026 ("Q1 2026") should be read in con

May 12, 2026 EX-99.4

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.4 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Alexander Dann, Chief Financial Officer and Vice President, Finance of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended March 31, 2026. 2. No

May 4, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 4, 2026 EX-99.1

Osisko Development Appoints Vice President, Construction Contracting and Commercial

EXHIBIT 99.1 Osisko Development Appoints Vice President, Construction Contracting and Commercial MONTREAL, May 04, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce the appointment of Ms. Sarah MacDonald as Vice President, Construction Contracting and Commercial, effective immediately. "Sarah's appointment to the

April 27, 2026 EX-99.1

TSX TRUST COMPANY

Exhibit 99.1 TSX TRUST COMPANY VIA ELECTRONIC TRANSMISSION April 27, 2026 TO ALL APPLICABLE EXCHANGES AND COMMISSIONS: RE: OSISKO DEVELOPMENT CORP. Confirmation of Notice of Record and Meeting Dates We are pleased to confirm that the Notice of Record and Meeting Dates was sent to The Canadian Depository for Securities. We advise the following with respect to the upcoming Annual and Special Meeting

April 27, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal exec

April 2, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

April 2, 2026 EX-99.1

Osisko Development Announces Annual Grant of Incentive Awards

EXHIBIT 99.1 Osisko Development Announces Annual Grant of Incentive Awards MONTREAL, April 01, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces that, as part of the annual compensation review conducted by its Board of Directors, it has granted an aggregate of (i) 1,104,400 stock options of the Company (the "Options"), and (ii

March 30, 2026 40-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 40-F ☐ Registration statement pursuant to Section 12 of the Securities Exchange Act of 1934 or ☒ Annual report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 For the fiscal year ended December 31, 2025 Commission File Number 001-41369 OSISKO DEVELOPMENT CORP. (Exact name of registrant as specifi

March 30, 2026 EX-99.19

CONSENT OF EXPERT

Exhibit 99.19 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.4

CERTIFICATIONS

Exhibit 99.4 CERTIFICATIONS I, Sean Roosen, certify that: 1. I have reviewed this annual report on Form 40-F of Osisko Development Corp.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respec

March 30, 2026 EX-99.2

OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Consolidated Financial Statements For the years ended December 31, 2025 and 2024

Exhibit 99.2 OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Consolidated Financial Statements For the years ended December 31, 2025 and 2024 Report of Independent Registered Public Accounting Firm To the Board of Directors and Shareholders of Osisko Development Corp. Opinion on the Financial Statements We have audited the accompanying consolidated statements of financial position of

March 30, 2026 EX-99.15

CONSENT OF EXPERT

Exhibit 99.15 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.13

CONSENT OF EXPERT

Exhibit 99.13 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.6

CERTIFICATION PURSUANT TO 18 U.S.C. §1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 99.6 CERTIFICATION PURSUANT TO 18 U.S.C. §1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the annual report of Osisko Development Corp. (the "Company") on Form 40-F for the fiscal year ended December 31, 2025 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Sean Roosen, Chief Executive Officer of the Co

March 30, 2026 EX-99.3

OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and twelve months ended December 31, 2025

Table of Contents Exhibit 99.3 OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and twelve months ended December 31, 2025 The following management discussion and analysis ("MD&A") of the operations and financial position of Osisko Development Corp. and its subsidiaries ("Osisko Development" or the "Company") for the three and twelve months ended December 31, 2025 ("Q4 20

March 30, 2026 EX-99.1

ANNUAL INFORMATION FORM FOR THE FINANCIAL YEAR ENDED DECEMBER 31, 2025 DATED AS OF MARCH 27, 2026

Table of Contents Exhibit 99.1 ANNUAL INFORMATION FORM FOR THE FINANCIAL YEAR ENDED DECEMBER 31, 2025 DATED AS OF MARCH 27, 2026 Table of Contents TABLE OF CONTENTS GENERAL MATTERS 1 CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION 1 CAUTIONARY NOTE TO U.S. INVESTORS REGARDING PREPARATION OF FINANCIAL INFORMATION 2 CAUTIONARY NOTE TO U.S. INVESTORS REGARDING THE USE OF MINERAL RESERVE AN

March 30, 2026 EX-99.1

Osisko Development Reports Fourth Quarter and Year-End 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise)

EXHIBIT 99.1 Osisko Development Reports Fourth Quarter and Year-End 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise) HIGHLIGHTS Q4 2025 (at December 31, 2025) Financial: ~$422.3 million in cash and cash equivalents; sold 3,970 ounces of gold from small-scale mining activities at the Tintic Project Financing: Completed a private placement financing for ~$

March 30, 2026 EX-99.23

CONSENT OF EXPERT

Exhibit 99.23 CONSENT OF EXPERT The undersigned hereby consents to the use of the report “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Information Form on Fo

March 30, 2026 EX-99.21

CONSENT OF EXPERT

Exhibit 99.21 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.18

CONSENT OF EXPERT

Exhibit 99.18 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.20

CONSENT OF EXPERT

Exhibit 99.20 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

March 30, 2026 EX-99.14

CONSENT OF EXPERT

Exhibit 99.14 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.16

CONSENT OF EXPERT

Exhibit 99.16 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.25

MINE SAFETY DISCLOSURE

Exhibit 99.25 MINE SAFETY DISCLOSURE Osisko Development Corp. (the “Company”) is committed to the health and safety of its employees and in providing an incident free workplace. The Company maintains a comprehensive health and safety program that includes extensive training for all employees and contractors, emergency response preparedness, site inspections, incident investigation, regulatory comp

March 30, 2026 EX-99.12

CONSENT OF EXPERT

Exhibit 99.12 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.7

CERTIFICATION PURSUANT TO 18 U.S.C. §1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 99.7 CERTIFICATION PURSUANT TO 18 U.S.C. §1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the annual report of Osisko Development Corp. (the "Company") on Form 40-F for the fiscal year ended December 31, 2025 as filed with the Securities and Exchange Commission on the date hereof (the "Report"), I, Alexander Dann, Chief Financial Officer and Vi

March 30, 2026 EX-97

OSISKO DEVELOPMENT CORP. CLAWBACK POLICY

Exhibit 97 OSISKO DEVELOPMENT CORP. CLAWBACK POLICY A.Application of Policy This Clawback Policy (this "Policy") applies in the event of any restatement ("Restatement") of the financial results of Osisko Development Corp. (the "Corporation") due to its material non-compliance with financial reporting requirements under applicable securities laws. This Policy does not apply to restatements that are

March 30, 2026 EX-99.22

CONSENT OF EXPERT

Exhibit 99.22 CONSENT OF EXPERT The undersigned hereby consents to the use of the report “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Information Form on Fo

March 30, 2026 EX-99.11

CONSENT OF EXPERT

Exhibit 99.11 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.8

Consent of Independent Registered Public Accounting Firm

Exhibit 99.8 Consent of Independent Registered Public Accounting Firm We hereby consent to the incorporation by reference in this Annual Report on Form 40-F for the year ended December 31, 2025 of Osisko Development Corp. of our report dated March 27, 2026, relating to the consolidated financial statements, which appears in Exhibit 99.2 incorporated by reference in this Annual Report on Form 40-F.

March 30, 2026 EX-99.5

CERTIFICATIONS

Exhibit 99.5 CERTIFICATIONS I, Alexander Dann, certify that: 1. I have reviewed this annual report on Form 40-F of Osisko Development Corp.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with res

March 30, 2026 EX-99.17

CONSENT OF EXPERT

Exhibit 99.17 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.24

CONSENT OF EXPERT

Exhibit 99.24 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.10

CONSENT OF EXPERT

Exhibit 99.10 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 30, 2026 EX-99.9

CONSENT OF EXPERT

Exhibit 99.9 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. The undersigned

March 16, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

March 16, 2026 EX-99.1

Osisko Development Announces Inclusion in the GDXJ

EXHIBIT 99.1 Osisko Development Announces Inclusion in the GDXJ MONTREAL, March 16, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce its inclusion in the VanEck Junior Gold Miners ETF ("GDXJ") pursuant to the GDXJ's semi-annual review and rebalancing announced on March 13, 2026, effective at the close of markets

March 9, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

March 9, 2026 EX-99.1

Osisko Development Announces Proceeds of $24.9 Million From Warrant Exercise

EXHIBIT 99.1 Osisko Development Announces Proceeds of $24.9 Million From Warrant Exercise MONTREAL, March 09, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces that it has received approximately C$24.9 million from the exercise of 5,625,031 common share purchase warrants of the Company (the "Warrants") held by funds advised by

March 2, 2026 EX-99.1

Osisko Development Announces Resumption of Planned Site Activities at the Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Announces Resumption of Planned Site Activities at the Cariboo Gold Project MONTREAL, March 02, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces the resumption of planned site activities at its Cariboo Gold Project (the "Project") in British Columbia, following a temporary suspension related to

March 2, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of March 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

February 20, 2026 EX-99.1

TSX TRUST COMPANY

Exhibit 99.1 TSX TRUST COMPANY VIA ELECTRONIC TRANSMISSION February 20, 2026 TO ALL APPLICABLE EXCHANGES AND COMMISSIONS: RE: OSISKO DEVELOPMENT CORP. Confirmation of Notice of Record and Meeting Dates We are pleased to confirm that the Notice of Record and Meeting Dates was sent to The Canadian Depository for Securities. We advise the following with respect to the upcoming Annual and Special Meet

February 20, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal e

February 12, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

February 12, 2026 EX-99.1

Osisko Development Provides Infill Drilling Update on Its 13,000-Meter Lowhee Program at Cariboo Gold Project; Intercepts Include 596.40 g/t Gold Over 2.0 Meters from 6.1 Meters Downhole, Including 2,293.56 g/t Gold Over 0.5 Meters from 6.6 Meters Do

EXHIBIT 99.1 Osisko Development Provides Infill Drilling Update on Its 13,000-Meter Lowhee Program at Cariboo Gold Project; Intercepts Include 596.40 g/t Gold Over 2.0 Meters from 6.1 Meters Downhole, Including 2,293.56 g/t Gold Over 0.5 Meters from 6.6 Meters Downhole HIGHLIGHTS 11,025 m of infill drilling completed (5,043 m new results) on 10-m drill spacing in 116 drill holes from August 2025 r

February 9, 2026 EX-99.1

Osisko Development Awards Project and Construction Management Services Contract for the Development of the Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Awards Project and Construction Management Services Contract for the Development of the Cariboo Gold Project MONTREAL, Feb. 09, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce that its wholly-owned subsidiary, Barkerville Gold Mines Ltd., has entered into a definitive Project and

February 9, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

February 5, 2026 EX-99.1

OSISKO DEVELOPMENT CORP. Code of Ethics TABLE OF CONTENTS

Exhibit 99.1 OSISKO DEVELOPMENT CORP. Code of Ethics TABLE OF CONTENTS SUMMARY 4 INTRODUCTION 5 OSISKO DEV’S CODE OF ETHICS 6 LAWS AND REGULATIONS 6 Compliance with Laws and Regulations 6 Lobbying 6 Dealing in Corporation’s Securities 6 Fair Competition 6 Competitors’ Information 7 DEALING WITH PUBLIC OR GOVERNMENT OFFICIALS 7 Anti-Bribery and Anti-Corruption 7 Gifts, Hospitality and Expenses 8 Fa

February 5, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal e

February 3, 2026 EX-99.1

Osisko Development Completes US$143.8 Million "Bought Deal" Public Offering of Common Shares Including Full Exercise of Over-Allotment Option

EXHIBIT 99.1 Osisko Development Completes US$143.8 Million "Bought Deal" Public Offering of Common Shares Including Full Exercise of Over-Allotment Option MONTREAL, Feb. 03, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce that it has completed its previously announced prospectus offering (the "Offering") of comm

February 3, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

February 2, 2026 EX-99.1

Osisko Development Appoints Vice President, Permitting and Compliance

EXHIBIT 99.1 Osisko Development Appoints Vice President, Permitting and Compliance MONTREAL, Feb. 02, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce the appointment of Ms. Sarah Harrison as Vice President, Permitting and Compliance, effective February 2, 2026. Ms. Harrison joins Osisko Development from JDS Ener

February 2, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of February 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

January 28, 2026 EX-99.3

Consent of Bennett Jones LLP

EXHIBIT 99.3 January 26, 2026 Consent of Bennett Jones LLP We hereby consent to the use of our name on the cover page and under the headings “Documents Filed as Part of the Registration Statement”, “Enforceability of Civil Liabilities” and “Legal Matters”, and to the reference to our name and use of our opinion under the heading “Eligibility for Investment”, in the prospectus supplement dated Janu

January 28, 2026 EX-99.1

Osisko Development Completes Sale of San Antonio Gold Project

EXHIBIT 99.1 Osisko Development Completes Sale of San Antonio Gold Project MONTREAL, Jan. 27, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) (collectively with its subsidiaries, "Osisko Development" or the "Company") is pleased to announce that it has completed the previously announced sale of its 100% interest in the San Antonio Gold Project ("San Antonio" or the "Project

January 28, 2026 SUPPL

PROSPECTUS SUPPLEMENT To the Short Form Base Shelf Prospectus dated December 23, 2025

TABLE OF CONTENTS  Filed pursuant to General Instruction II.L of Form F-10  File No. 333-292328 PROSPECTUS SUPPLEMENT To the Short Form Base Shelf Prospectus dated December 23, 2025 New IssueJanuary 27, 2026 OSISKO DEVELOPMENT CORP. US$125,000,940 35,311,000 Common Shares Price: US$3.54 per Common Share Osisko Development Corp. (the “Corporation” or “ODV”) is hereby qualifying the distribution of

January 28, 2026 EX-99.4

January 26, 2026

Exhibit 99.4 January 26, 2026 By EDGAR Osisko Development Corp. 1100, av des Canadiens-de-Montréal Suite 300, P.O. Box 211 Montréal, QC H3B 2S2 Dear Sirs/Mesdames: Osisko Development Corp. Prospectus Supplement dated January 26, 2026 We refer you to the prospectus supplement dated January 26, 2026 (the “Prospectus Supplement”) to the short form base shelf prospectus of Osisko Development Corp. dat

January 28, 2026 EX-99.5

CONSENT OF QUALIFIED PERSON

Exhibit 99.5 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to being named, in the prospectus supplement forming part of the Registration Statement on Form F-10, as amended (File No. 333-292328) (the “Registration Statement”), of Osisko Development Corp. (the “Company”), as a qualified person who reviewed and takes responsibility for the scientific, geological, and technical informati

January 28, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 Montréal, Québec H3B 2S2

January 28, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

January 28, 2026 EX-99.2

OSISKO DEVELOPMENT CORP.

Exhibit 99.2 January 26, 2026 OSISKO DEVELOPMENT CORP. BOUGHT DEAL TREASURY OFFERING OF COMMON SHARES A final base shelf prospectus containing important information relating to the securities described in this document has been filed with the securities regulatory authorities in each of the provinces and territories of Canada. The final base shelf prospectus, any applicable shelf prospectus supple

January 28, 2026 EX-99.1

UNDERWRITING AGREEMENT

Exhibit 99.1 UNDERWRITING AGREEMENT January 27, 2026 Osisko Development Corp. 1100, av des Canadiens-de-Montréal Suite 300, P.O. Box 211 Montréal, QC H3B 2S2 Attention: Sean Roosen, Chairman and Chief Executive Officer National Bank Financial Inc. (“NBF”), RBC Dominion Securities Inc. and Cantor Fitzgerald Canada Corporation, as co-bookrunners and co-lead underwriters (the “Lead Underwriters”), an

January 27, 2026 EX-99.1

Osisko Development Announces US$125 Million Bought Deal Public Offering of Common Shares to Advance Mineral Resource-to-Reserve Conversion Toward Mine Plan Integration at the Cariboo Gold Project THE BASE SHELF PROSPECTUS IS ACCESSIBLE, AND THE CANAD

EXHIBIT 99.1 Osisko Development Announces US$125 Million Bought Deal Public Offering of Common Shares to Advance Mineral Resource-to-Reserve Conversion Toward Mine Plan Integration at the Cariboo Gold Project THE BASE SHELF PROSPECTUS IS ACCESSIBLE, AND THE CANADIAN PROSPECTUS SUPPLEMENT WILL BE ACCESSIBLE WITHIN TWO BUSINESS DAYS, UNDER THE COMPANY'S ISSUER PROFILE ON SEDAR+. MONTREAL, Jan. 26, 2

January 27, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

January 26, 2026 SUPPL

Subject to completion, dated January 26, 2026 PRELIMINARY PROSPECTUS SUPPLEMENT To the Short Form Base Shelf Prospectus dated December 23, 2025

TABLE OF CONTENTS  Filed pursuant to General Instruction II.L of Form F-10  File No. 333-292328 The information contained in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell and are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is n

January 23, 2026 EX-99.1

Osisko Development Reports Contractor Fatality at the Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Reports Contractor Fatality at the Cariboo Gold Project MONTREAL, Jan. 23, 2026 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") regrets to report that on January 22, 2026, a contractor working at surface suffered a fatal injury following an isolated incident at the Cariboo Gold Project (the "Project"), locat

January 23, 2026 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of January 2026 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

December 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

December 29, 2025 EX-99.1

OSISKO DEVELOPMENT AND ELECTRIC ELEMENTS FILE EARLY WARNING REPORT FOR NIOBAY METALS INC.

Exhibit 99.1 OSISKO DEVELOPMENT AND ELECTRIC ELEMENTS FILE EARLY WARNING REPORT FOR NIOBAY METALS INC. Montreal, Québec, December 23, 2025 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces that, on December 18, 2025, Osisko Development acquired, indirectly through its wholly-owned subsidiary, Barkerville Gold Mines Ltd. ("BGM"), 8,571,429 units of

December 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

December 29, 2025 EX-99.1

FORM 62-103F1 EARLY WARNING REPORT

Exhibit 99.1 FORM 62-103F1 EARLY WARNING REPORT This report updates information disclosed in previous early warning reports filed by (i) OR Royalties Inc. (formerly, known as Osisko Gold Royalties Ltd) ("OR") dated November 27, 2020, which disclosed Osisko Development Corp. ("ODV") (a controlled subsidiary of OR at that time) and Barkerville Gold Mines Ltd. ("BGM") (a wholly-owned subsidiary of OD

December 23, 2025 F-10/A

As filed with the Securities and Exchange Commission on December 23, 2025

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on December 23, 2025 Registration No.

December 22, 2025 EX-5.12

CONSENT OF QUALIFIED PERSON

Exhibit 5.12 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

December 22, 2025 EX-5.6

CONSENT OF QUALIFIED PERSON

Exhibit 5.6 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each ca

December 22, 2025 EX-FILING FEES

Security Type

Calculation of Filing Fee Tables F-10 Osisko Development Corp. Table 1: Newly Registered Securities ☐Not Applicable Security Type Security Class Title Fee Calculation Rule or Instruction Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Equity Common Shares 457(o) Debt Debt Securities 457(o) Other Warrants 457(o) Other S

December 22, 2025 EX-5.13

CONSENT OF QUALIFIED PERSON

Exhibit 5.13 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

December 22, 2025 EX-5.16

CONSENT OF QUALIFIED PERSON

Exhibit 5.16 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

December 22, 2025 EX-5.10

CONSENT OF QUALIFIED PERSON

Exhibit 5.10 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

December 22, 2025 EX-5.3

CONSENT OF QUALIFIED PERSON

Exhibit 5.3 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each ca

December 22, 2025 EX-5.4

CONSENT OF QUALIFIED PERSON

Exhibit 5.4 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each ca

December 22, 2025 EX-5.14

CONSENT OF QUALIFIED PERSON

Exhibit 5.14 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

December 22, 2025 EX-5.8

CONSENT OF QUALIFIED PERSON

Exhibit 5.8 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each ca

December 22, 2025 EX-5.15

finalCONSENT OF QUALIFIED PERSON

Exhibit 5.15 finalCONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in e

December 22, 2025 EX-5.9

CONSENT OF QUALIFIED PERSON

Exhibit 5.9 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each cas

December 22, 2025 EX-5.5

CONSENT OF QUALIFIED PERSON

Exhibit 5.5 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each ca

December 22, 2025 EX-5.11

CONSENT OF QUALIFIED PERSON

Exhibit 5.11 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

December 22, 2025 EX-5.7

CONSENT OF QUALIFIED PERSON

Exhibit 5.7 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each ca

December 22, 2025 F-10

As filed with the Securities and Exchange Commission on December 19, 2025

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on December 19, 2025 Registration No.

December 22, 2025 F-X

UNITED STATES Securities and Exchange Commission Washington, D.C. 20549 FORM F-X APPOINTMENT OF AGENT FOR SERVICE OF PROCESS AND UNDERTAKING

UNITED STATES Securities and Exchange Commission Washington, D.C. 20549 FORM F-X APPOINTMENT OF AGENT FOR SERVICE OF PROCESS AND UNDERTAKING A. Name of issuer or person filing (“Filer”): Osisko Development Corp. B. (1) This is x an original filing for the Filer. ¨ an amended filing for the Filer. C. Identify the filing in conjunction with which this Form is being filed: Name of registrant: Osisko

December 22, 2025 EX-7.1

Osisko Development Corp. as Issuer [ ] as Trustee Dated as of [ ] Osisko Development Corp. Reconciliation and tie between Trust Indenture Act of 1939 and Indenture, dated as of [ ]

Exhibit 7.1 Osisko Development Corp. as Issuer AND [ ] as Trustee Indenture Dated as of [ ] Osisko Development Corp. Reconciliation and tie between Trust Indenture Act of 1939 and Indenture, dated as of [ ] Trust Indenture Act Section Indenture Section §310(a)(1) 607 (a)(2) 607 (b) 608 §312(b) 701 (c) 701 §313(a) 702 (b)(1) 702 (b)(2) 702 (c) 702 (d) 702 §314(a) 703 (a)(4) 904 (c)(1) 102 (c)(2) 10

December 18, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal e

December 18, 2025 EX-99.1

FORM 51-102F3 MATERIAL CHANGE REPORT

Exhibit 99.1 FORM 51-102F3 MATERIAL CHANGE REPORT Item 1 Name and Address of the Company Osisko Development Corp. (the "Company") 1100 Avenue des Canadiens-des-Montréal, Suite 300 Montréal, Québec H3B 2S2 Item 2 Date of Material Change October 29, 2025 Item 3 News Release A news release with respect to the material change referred to in this report was issued by the Company through GlobeNewswire o

December 18, 2025 424B3

Osisko Development Corporation Up to 104,751,318 Common Shares

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(3)  Registration No. 333-290216 PROSPECTUS Osisko Development Corporation Up to 104,751,318 Common Shares This prospectus relates to the resale from time to time of up to 104,751,318 common shares by the selling shareholders identified in this prospectus. We are registering these common shares on behalf of the selling shareholders, to be offered and

December 15, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

December 15, 2025 EX-99.1

Osisko Development Provides Infill Drilling Update on Its 13,000-m Program at Cariboo Gold Project; Intercepts Include 8.56 g/t Au Over 8.5m from 60.5m Depth, and 130.32 g/t Au Over 0.5m from 83.5m Depth

EXHIBIT 99.1 Osisko Development Provides Infill Drilling Update on Its 13,000-m Program at Cariboo Gold Project; Intercepts Include 8.56 g/t Au Over 8.5m from 60.5m Depth, and 130.32 g/t Au Over 0.5m from 83.5m Depth HIGHLIGHTS 5,983 m of infill drilling completed (3,704 m of new results) on 10-m drill spacing in 62 drill holes from August 2025, representing ~44% of the total planned 13,000-m infi

December 12, 2025 CORRESP

OSISKO DEVELOPMENT CORP. 1100 Avenue des Canadiens-de-Montreal Suite 300 Montreal, Quebec H3B 2S2

OSISKO DEVELOPMENT CORP. 1100 Avenue des Canadiens-de-Montreal Suite 300 Montreal, Quebec H3B 2S2 Canada VIA EDGAR December 12, 2025 Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549 Attn: Michael Purcell Re: Osisko Development Corp. Registration Statement on Form F-3 (File No. 333-290216) Request for Acceleration of Effective Date Ladies

December 11, 2025 F-3/A

As filed with the Securities and Exchange Commission on December 10, 2025

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on December 10, 2025 Registration No.

December 8, 2025 EX-99.1

Osisko Development Launches Fully-Funded 70,000-Meter Exploration Drilling Campaign Targeting New Discoveries at Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Launches Fully-Funded 70,000-Meter Exploration Drilling Campaign Targeting New Discoveries at Cariboo Gold Project HIGHLIGHTS1 Fully-funded 70,000-meter exploration drill program launched with two drill rigs already operating at the Cariboo Gold Project site, and ramping up to six drill rigs as the program advances through the end of 2026 Priority exploration target

December 8, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of December 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

November 24, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

November 24, 2025 EX-99.1

Osisko Development Announces Agreement to Divest Non-Core San Antonio Gold Project

EXHIBIT 99.1 Osisko Development Announces Agreement to Divest Non-Core San Antonio Gold Project MONTREAL, Nov. 24, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce that it has entered into a securities purchase agreement dated November 21, 2025 (the "Purchase Agreement") with Axo Copper Corp. (TSXV:AXO) ("Axo") t

November 10, 2025 EX-99.4

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.4 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Alexander Dann, Chief Financial Officer and Vice President, Finance of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended September 30, 2025. 2

November 10, 2025 EX-99.1

OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three and nine months ended September 30, 2025 and 2024

Exhibit 99.1 OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three and nine months ended September 30, 2025 and 2024 Osisko Development Corp. Consolidated Statements of Financial Position As at September 30, 2025 and December 31 2024 (Unaudited) (Tabular amounts expressed in thousands of Canadian dollars) September

November 10, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal e

November 10, 2025 EX-99.2

OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and nine months ended September 30, 2025

Table of Contents Exhibit 99.2 OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and nine months ended September 30, 2025 The following management discussion and analysis ("MD&A") of the operations and financial position of Osisko Development Corp. and its subsidiaries ("Osisko Development" or the "Company") for the three and nine months ended September 30, 2025 ("Q3 2025

November 10, 2025 EX-99.1

Osisko Development Reports Third Quarter 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise)

EXHIBIT 99.1 Osisko Development Reports Third Quarter 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise) HIGHLIGHTS Q3 2025 (at September 30, 2025) ~$401.4 million in cash and cash equivalents Drawn ~$137.2 million (US$100.0 million) under the US$450 million Appian financing facility executed during the quarter Completed private placements for ~$280.4 mill

November 10, 2025 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Sean Roosen, Chair of the Board and Chief Executive Officer of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended September 30, 2025. 2. No mis

November 10, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

November 3, 2025 EX-99.1

Osisko Development Strengthens Technical Team With Appointment of Vice President, Exploration

EXHIBIT 99.1 Osisko Development Strengthens Technical Team With Appointment of Vice President, Exploration MONTREAL, Nov. 03, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce the appointment of Mr. Scott Smith as Vice President, Exploration effective November 1, 2025. Mr. Smith joins from Prime Mining Corp. where

November 3, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of November 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2

October 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

October 29, 2025 EX-99.1

OSISKO DEVELOPMENT CLOSES C$82.5 MILLION PRIVATE PLACEMENT

Exhibit 99.1 ODV NYSE TSXV OSISKO DEVELOPMENT CLOSES C$82.5 MILLION PRIVATE PLACEMENT Montreal, Québec, October 29, 2025 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce the successful closing of its previously-announced oversubscribed private placement offering of 15,409,798 common shares of the Company (the "Common Shares") for aggr

October 27, 2025 EX-99.1

Osisko Development Files Early Warning Report Regarding Falco Resources Ltd.

EXHIBIT 99.1 Osisko Development Files Early Warning Report Regarding Falco Resources Ltd. MONTREAL, Oct. 27, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") reports that, on October 17, 2025, Osisko Development acquired, indirectly through its wholly-owned subsidiary, Barkerville Gold Mines Ltd. ("BGM"), 6,250,000 units of Falco Resou

October 27, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

October 15, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

October 15, 2025 CORRESP

* * *

October 15, 2025 VIA EDGAR U.S. Securities and Exchange Commission 100 F. Street, N.E. Washington, D.C. 20549 Attention: Michael Purcell and Irene Barberena-Meissner Re: Osisko Development Corp. Registration Statement on Form F-3 Filed September 12, 2025 File No. 333-290216 Ladies and Gentlemen: I am submitting this letter on behalf of Osisko Development Corp. (the “Company”), in response to the w

October 15, 2025 EX-99.1

OSISKO DEVELOPMENT ANNOUNCES FURTHER UPSIZE OF PREVIOUSLY ANNOUNCED "BOUGHT DEAL" OFFERING Total Upsized Offering of C$75 Million

Exhibit 99.1 ODV NYSE TSXV OSISKO DEVELOPMENT ANNOUNCES FURTHER UPSIZE OF PREVIOUSLY ANNOUNCED "BOUGHT DEAL" OFFERING Total Upsized Offering of C$75 Million Montreal, Québec, October 15, 2025 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce that, as a result of excess demand, it has entered into a further amending agreement (the "Amen

October 9, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

October 9, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

October 9, 2025 EX-99.1

OSISKO DEVELOPMENT ANNOUNCES UPSIZING OF PREVIOUSLY ANNOUNCED "BOUGHT DEAL" LIFE OFFERING; ADDITIONAL CONCURRENT PRIVATE PLACEMENT Total Upsized Offering of C$60 Million

Exhibit 99.1 ODV NYSE TSXV OSISKO DEVELOPMENT ANNOUNCES UPSIZING OF PREVIOUSLY ANNOUNCED "BOUGHT DEAL" LIFE OFFERING; ADDITIONAL CONCURRENT PRIVATE PLACEMENT Total Upsized Offering of C$60 Million Montreal, Québec, October 9, 2025 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce that, as a result of excess demand, it has entered into

October 9, 2025 EX-99.1

OSISKO DEVELOPMENT ANNOUNCES C$30 MILLION BOUGHT DEAL LIFE OFFERING OF NATIONAL AND BC FLOW-THROUGH SHARES

Exhibit 99.1 ODV NYSE TSXV OSISKO DEVELOPMENT ANNOUNCES C$30 MILLION BOUGHT DEAL LIFE OFFERING OF NATIONAL AND BC FLOW-THROUGH SHARES Montreal, Québec, October 8, 2025 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce that it has entered into an agreement with certain underwriters, pursuant to which the underwriters have agreed to purc

October 6, 2025 EX-99.1

Osisko Development Provides Infill Drilling Update on Its 13,000-Meter Lowhee Program at Cariboo Gold Project; Intercepts Include 45.24 G/T Gold Over 3.0 Meters, Including 233.92 G/T Gold Over 0.5 Meters

EXHIBIT 99.1 Osisko Development Provides Infill Drilling Update on Its 13,000-Meter Lowhee Program at Cariboo Gold Project; Intercepts Include 45.24 G/T Gold Over 3.0 Meters, Including 233.92 G/T Gold Over 0.5 Meters HIGHLIGHTS 2,279 m of infill drilling completed on 10-m drill spacing in 24 drill holes from August 2025 representing ~17.5% of the total planned 13,000-m infill program Highlight int

October 6, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S

September 30, 2025 LETTER

LETTER

September 30, 2025 Sean Roosen Chief Executive Officer Osisko Development Corp. 1100 Avenue des Canadiens-de-Montr al Suite 300 Montr al, Qu bec H3B 2S2 Canada Re: Osisko Development Corp. Registration Statement on Form F-3 Filed September 12, 2025 File No. 333-290216 Dear Sean Roosen: We have conducted a limited review of your registration statement and have the following comments. Please respond

September 12, 2025 EX-23.13

CONSENT OF QUALIFIED PERSON

Exhibit 23.13 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each

September 12, 2025 EX-3.1

Form 4 Canada Business Corporations Act (CBCA) (s. 27 or 177) Formulaire 4 Loi canadienne sur les sociétés par actions (LCSA) (art. 27 ou 177) Articles of Amendment Clauses modificatrices Corporate name Dénomination sociale 1 Osisko Development Corp.

Exhibit 3.1 Certificate of Amendment Canada Business Corporations Act Loi canadienne sur les sociétés par actions Certificat de modification Osisko Development Corp. Osisko Développement Corp. 1252807-0 Corporate name / Dénomination sociale Corporation number / Numéro de société Hantz Prosper Date of amendment (YYYY-MM-DD) Date de modification (AAAA-MM-JJ) Director / Directeur 2022-05-03 I HEREBY

September 12, 2025 EX-23.8

CONSENT OF QUALIFIED PERSON

Exhibit 23.8 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

September 12, 2025 EX-23.10

CONSENT OF QUALIFIED PERSON

Exhibit 23.10 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

September 12, 2025 EX-23.9

CONSENT OF QUALIFIED PERSON

Exhibit 23.9 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

September 12, 2025 EX-23.15

CONSENT OF QUALIFIED PERSON

Exhibit 23.15 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each

September 12, 2025 EX-23.17

CONSENT OF QUALIFIED PERSON

Exhibit 23.17 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each

September 12, 2025 EX-23.16

CONSENT OF QUALIFIED PERSON

Exhibit 23.16 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each

September 12, 2025 F-3

As filed with the Securities and Exchange Commission on September 12, 2025

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on September 12, 2025 Registration No.

September 12, 2025 EX-23.12

CONSENT OF QUALIFIED PERSON

Exhibit 23.12 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each

September 12, 2025 EX-10.2

OSISKO DEVELOPMENT CORP. SUBSCRIPTION AGREEMENT (UNITS)

Exhibit 10.2 NON-BROKERED (ISSUER DIRECT) THE SECURITIES TO WHICH THIS SUBSCRIPTION AGREEMENT RELATES HAVE NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE "U.S. SECURITIES ACT"), OR UNDER ANY OTHER APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES, AND MAY NOT BE OFFERED OR SOLD TO OR FOR THE ACCOUNT OR BENEFIT OF PERSONS IN THE UNITED STATES OR U.S.

September 12, 2025 EX-23.7

CONSENT OF QUALIFIED PERSON

Exhibit 23.7 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each c

September 12, 2025 EX-FILING FEES

Security Type

Calculation of Filing Fee Tables F-3 Osisko Development Corp. Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward In

September 12, 2025 EX-23.14

CONSENT OF QUALIFIED PERSON

Exhibit 23.14 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each

September 12, 2025 EX-23.11

CONSENT OF QUALIFIED PERSON

Exhibit 23.11 CONSENT OF QUALIFIED PERSON The undersigned hereby consents to the use of the technical report entitled, “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” dated June 11, 2025, with an effective date of April 25, 2025, and the information derived therefrom, as well as references to the undersigned’s name, in each

September 12, 2025 EX-10.1

OSISKO DEVELOPMENT CORP. SUBSCRIPTION AGREEMENT (UNITS)

Exhibit 10.1 CANADA, USA (QIB), OFFSHORE THE SECURITIES TO WHICH THIS SUBSCRIPTION AGREEMENT RELATES HAVE NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE "U.S. SECURITIES ACT"), OR UNDER ANY OTHER APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES, AND MAY NOT BE OFFERED OR SOLD TO OR FOR THE ACCOUNT OR BENEFIT OF PERSONS IN THE UNITED STATES OR U.S. P

September 9, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 Commission File Number: 001-

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of September 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B

September 9, 2025 EX-99.1

Osisko Development Intercepts 57.29 g/t Gold Over 3.05 Meters, 625.95 g/t Gold Over 0.5 Meters and 15.26 g/t Gold Over 4.4 Meters in Lowhee Infill Drilling at Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Intercepts 57.29 g/t Gold Over 3.05 Meters, 625.95 g/t Gold Over 0.5 Meters and 15.26 g/t Gold Over 4.4 Meters in Lowhee Infill Drilling at Cariboo Gold Project MONTREAL, Sept. 08, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce results from its infill and exploration diamond dril

August 29, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-413

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal exe

August 29, 2025 EX-99.3

OSISKO DEVELOPMENT CORP. as the Corporation - and - TSX TRUST COMPANY as the Warrant Agent WARRANT INDENTURE Providing for the Issue of up to 49,532,661 Warrants Dated as of August 15, 2025 TABLE OF CONTENTS

Exhibit 99.3 EXECUTION COPY OSISKO DEVELOPMENT CORP. as the Corporation - and - TSX TRUST COMPANY as the Warrant Agent WARRANT INDENTURE Providing for the Issue of up to 49,532,661 Warrants Dated as of August 15, 2025 TABLE OF CONTENTS Page ARTICLE 1 INTERPRETATION 2 1.1 Definitions 2 1.2 Gender and Number 6 1.3 Construction 7 1.4 Day not a Business Day 7 1.5 Time of the Essence 7 1.6 Monetary Ref

August 29, 2025 EX-99.4

FORM 51-102F3 MATERIAL CHANGE REPORT

Exhibit 99.4 FORM 51-102F3 MATERIAL CHANGE REPORT Item 1 Name and Address of the Company Osisko Development Corp. (the "Company") 1100 Avenue des Canadiens-des-Montréal, Suite 300 Montréal, Québec H3B 2S2 Item 2 Date of Material Change August 15, 2025 Item 3 News Release A news release with respect to the material change referred to in this report was issued by the Company through GlobeNewswire on

August 29, 2025 EX-99.1

INVESTOR RIGHTS AGREEMENT OSISKO DEVELOPMENT CORP. - and - DOUBLE ZERO CAPITAL LP AUGUST 15, 2025 TABLE OF CONTENTS

Exhibit 99.1 INVESTOR RIGHTS AGREEMENT OSISKO DEVELOPMENT CORP. - and - DOUBLE ZERO CAPITAL LP AUGUST 15, 2025 TABLE OF CONTENTS ARTICLE I INTERPRETATION 1 1.01 Definitions 1 1.02 Extended Meanings 3 1.03 Interpretation Not Affected by Headings, Etc. 3 1.04 Statutory References 3 1.05 Monetary References 4 1.06 Day Not a Business Day 4 ARTICLE II BOARD NOMINATION RIGHTS 4 2.01 Investor Nomination

August 29, 2025 EX-99.2

UNDERWRITING AGREEMENT

Exhibit 99.2 EXECUTION COPY UNDERWRITING AGREEMENT August 15, 2025 Osisko Development Corp. 1100, av des Canadiens-de-Montréal Suite 300, P.O. Box 211 Montréal, QC H3B 2S2 Attention:      Sean Roosen, Chairman and Chief Executive Officer BMO Nesbitt Burns Inc. and RBC Dominion Securities Inc., as joint lead managers and joint bookrunners (together, the “Joint Bookrunners”), and Cantor Fitzgerald C

August 20, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-413

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

August 20, 2025 EX-99.1

Osisko Development Announces Grant of Deferred Share Units

EXHIBIT 99.1 Osisko Development Announces Grant of Deferred Share Units MONTREAL, Aug. 20, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces that it has granted 58,824 deferred share units ("DSUs") of the Company to Ms. Susan Craig, an independent director, as part of her recent appointment to the Company's board of directors

August 15, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execu

August 15, 2025 EX-99.1

FORM 51-102F3 MATERIAL CHANGE REPORT

Exhibit 99.1 FORM 51-102F3 MATERIAL CHANGE REPORT Item 1 Name and Address of the Company Osisko Development Corp. (the "Corporation") 1100 Avenue des Canadiens-des-Montréal, Suite 300 Montréal, Québec, H3B 2S2 Item 2 Date of Material Change July 21, 2025 Item 3 News Release A news release with respect to the material change referred to in this report was issued by the Corporation through GlobeNews

August 15, 2025 EX-99.1

OSISKO DEVELOPMENT CLOSES US$203 MILLION PRIVATE PLACEMENT FINANCING

Exhibit 99.1 OSISKO DEVELOPMENT CLOSES US$203 MILLION PRIVATE PLACEMENT FINANCING Montreal, Québec, August 15, 2025 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce the successful closing of its previously announced private placement of 99,065,330 units of the Company (each, a "Unit") at a price of US$2.05 per Unit (the "Issue Price")

August 15, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-413

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal exe

August 15, 2025 EX-99.1

CREDIT AGREEMENT BARKERVILLE GOLD MINES LTD. as Borrower The Guarantors party hereto from time to time as Guarantors APPIAN ODV (JERSEY) LTD AND THE OTHER LENDERS PARTY HERETO FROM TIME TO TIME as Lenders TSX TRUST COMPANY as Collateral Agent APPIAN

Exhibit 99.1 CREDIT AGREEMENT BETWEEN BARKERVILLE GOLD MINES LTD. as Borrower -and- The Guarantors party hereto from time to time as Guarantors -and- APPIAN ODV (JERSEY) LTD AND THE OTHER LENDERS PARTY HERETO FROM TIME TO TIME as Lenders -and- TSX TRUST COMPANY as Collateral Agent -and- APPIAN ODV (JERSEY) LTD as Administrative Agent July 21, 2025 TABLE OF CONTENTS Page Article 1 INTERPRETATION 1

August 15, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execu

August 13, 2025 EX-99.2

OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and six months ended June 30, 2025

Table of Contents Exhibit 99.2 OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and six months ended June 30, 2025 The following management discussion and analysis ("MD&A") of the operations and financial position of Osisko Development Corp. and its subsidiaries ("Osisko Development" or the "Company") for the three and six months ended June 30, 2025 ("Q2 2025") should be

August 13, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-413

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal exe

August 13, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-413

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of August 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

August 13, 2025 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Sean Roosen, Chair of the Board and Chief Executive Officer of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended June 30, 2025. 2. No misrepre

August 13, 2025 EX-99.4

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.4 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Alexander Dann, Chief Financial Officer and Vice President, Finance of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended June 30, 2025. 2. No

August 13, 2025 EX-99.1

OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three and six months ended June 30, 2025 and 2024

Exhibit 99.1 OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three and six months ended June 30, 2025 and 2024 Osisko Development Corp. Consolidated Statements of Financial Position As at June 30, 2025 and December 31 2024 (Unaudited) (Tabular amounts expressed in thousands of Canadian dollars) June 30, December 31,

August 13, 2025 EX-99.1

Osisko Development Reports Second Quarter 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise)

EXHIBIT 99.1 Osisko Development Reports Second Quarter 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise) MONTREAL, Aug. 12, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") reports its financial and operating results for the three months ended June 30, 2025 ("Q2 2025"). Q2 2025 HIGHLIGHTS Oper

August 1, 2025 EX-99.1

OSISKO DEVELOPMENT ANNOUNCES US$195 MILLION FINANCING

Exhibit 99.1 NEWS RELEASE OSISKO DEVELOPMENT ANNOUNCES US$195 MILLION FINANCING Montreal, Québec, July 31, 2025 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces today that it has entered into an agreement with a syndicate of underwriters, under which the underwriters have agreed to buy, on a "bought deal" private placement basis, 58,560,000 units

August 1, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execu

July 21, 2025 EX-99.1

Osisko Development Secures US$450 Million Financing Facility to Develop the Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Secures US$450 Million Financing Facility to Develop the Cariboo Gold Project HIGHLIGHTS US$450 million project loan facility secured from new strategic partner Appian Capital Advisory to fund the development and construction of the Cariboo Gold Project in B.C., Canada US$100 million initial draw enables the Company to accelerate project pre-construction activities

July 21, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (

July 21, 2025 EX-99.2

Notice of Annual and special Meeting of Shareholders and Management Information Circular March 26, 2025

Exhibit 99.2 Notice of Annual and special Meeting of Shareholders and Management Information Circular March 26, 2025 Our annual and special meeting of shareholders will be held on May 7, 2025, at 1:30 P.M. (Eastern Time) at 1 Pl. Ville-Marie Suite 2500, Montréal, QC H3B 1R1, Canada. Shareholders may exercise their rights by attending the meeting or completing a form of proxy. If you have questions

July 21, 2025 EX-99.1

Osisko Development Corp. Annual Report prepared in accordance with the Fighting Against Forced Labour and Child Labour in Supply Chains Act For the Financial Year Ended December 31, 2024

Exhibit 99.1 Osisko Development Corp. Annual Report prepared in accordance with the Fighting Against Forced Labour and Child Labour in Supply Chains Act For the Financial Year Ended December 31, 2024 1.       Introduction In this annual report ("Report") made in accordance with the Fighting Against Forced Labour and Child Labour in Supply Chains Act, S.C. 2023, c.-9 ("Act"), references to "Osisko

July 21, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execu

July 7, 2025 EX-99.1

CORRECTION - Osisko Development Announces Positive Bulk Tonnage Ore Sorting Results for the Cariboo Gold Project

EXHIBIT 99.1 CORRECTION - Osisko Development Announces Positive Bulk Tonnage Ore Sorting Results for the Cariboo Gold Project In a release issued under the same headline on July 7, 2025, by Osisko Development Corp. (NYSE: ODV, TSXV: ODV), please note that the highlights section and eleventh paragraph have been updated to reflect the correct reference to gold recovery for the 6–10 mm fraction of "9

July 7, 2025 EX-99.1

Osisko Development Announces Positive Bulk Tonnage Ore Sorting Results for the Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Announces Positive Bulk Tonnage Ore Sorting Results for the Cariboo Gold Project HIGHLIGHTS X-ray transmission (XRT) ore sorter testwork of a ~80 tonne sample taken from the Cariboo underground achieved positive results consistent with 2025 FS parameters 42-55% waste rejection with 84-89% gold recovery achieved by sorting mid-size and oversize sample material includ

July 7, 2025 6-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K/A Amendment No. 1 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K/A Amendment No. 1 REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal

July 7, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of July 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (

June 16, 2025 EX-99.1

Osisko Development Appoints Susan Craig to Board of Directors as Independent Director

EXHIBIT 99.1 Osisko Development Appoints Susan Craig to Board of Directors as Independent Director MONTREAL, June 16, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce the appointment of Ms. Susan Craig as independent director to the Company's board of directors effective immediately. "We are very pleased to welco

June 16, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (

June 12, 2025 EX-99.1

Date and Signature Page

Exhibit 99.1 Prepared by the following Qualified Persons: ▪ Mathieu Belisle, P.Eng...............BBA Engineering Ltd. ▪ Amanda Fitch, P.Eng................BBA Engineering Ltd. ▪ Sebastien Guido, P.Eng............Alius Mine Consulting Inc. ▪ Philip Clark, P.Eng......................Clean Energy Consulting Inc. ▪ Rob Griffith, P.Eng. ....................Falkirk Environmental Consultants Ltd. ▪ Kathe

June 12, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execu

June 12, 2025 EX-99.1

Osisko Development Files NI 43-101 Feasibility Study Technical Report for the Cariboo Gold Project

EXHIBIT 99.1 Osisko Development Files NI 43-101 Feasibility Study Technical Report for the Cariboo Gold Project MONTREAL, June 11, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces the filing of a technical report (the "Technical Report") prepared in accordance with National Instrument 43-101 – Standards of Disclosure for Mine

June 12, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of June 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (

May 30, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 30, 2025 EX-2.01

Extractive Sector Transparency Measures Act - Annual Report

UNCLASSIFIED - NON CLASSIFIÉ Extractive Sector Transparency Measures Act - Annual Report Reporting Entity Name Osisko Development Corp.

May 30, 2025 EX-99.1

Osisko Development to Complete Third Deferred Payment Installment in Connection with the Tintic Acquisition; Engages Resource Stock Digest

EXHIBIT 99.1 Osisko Development to Complete Third Deferred Payment Installment in Connection with the Tintic Acquisition; Engages Resource Stock Digest MONTREAL, May 29, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces that, in accordance with the terms of the Company's previously-completed acquisition in May 2022 of a 100% o

May 30, 2025 SD

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report OSISKO DEVELOPMENT CORP. (Exact name of registrant as specified in its charter)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM SD Specialized Disclosure Report OSISKO DEVELOPMENT CORP. (Exact name of registrant as specified in its charter) Canada 001 41369 (State or other jurisdiction of incorporation) (Commission file number) 1100 Ave. des Canadiens-de-Montréal, Montréal, Quebec, Canada H3B 2S2 (Address of principal executive offices) (Zip code)

May 14, 2025 EX-99.1

Osisko Development Announces Annual Grant of Incentive Awards

EXHIBIT 99.1 Osisko Development Announces Annual Grant of Incentive Awards MONTREAL, May 13, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces that, as part of the annual compensation review of its Board of Directors, it has granted an aggregate of (i) 1,273,900 stock options of the Company (the "Options") to certain senior of

May 14, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 8, 2025 EX-99.1

Osisko Development Announces Results of Shareholders' Meeting

EXHIBIT 99.1 Osisko Development Announces Results of Shareholders' Meeting MONTREAL, May 07, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announces the results of its annual and special meeting of shareholders of the Company (the "Meeting") held on May 7, 2025. A total of 80,489,188 common shares were voted at the Meeting, represen

May 8, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 7, 2025 EX-99.4

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.4 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Alexander Dann, Chief Financial Officer and Vice President, Finance of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended March 31, 2025. 2. No

May 7, 2025 EX-99.2

OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three months ended March 31, 2025

Table of Contents Exhibit 99.2 OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three months ended March 31, 2025 The following management discussion and analysis ("MD&A") of the operations and financial position of Osisko Development Corp. and its subsidiaries ("Osisko Development" or the "Company") for the three months ended March 31, 2025 ("Q1 2025") should be read in conju

May 7, 2025 EX-99.1

Osisko Development Reports First Quarter 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise)

EXHIBIT 99.1 Osisko Development Reports First Quarter 2025 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise) MONTREAL, May 06, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") reports its financial and operating results for the three months ended March 31, 2025 ("Q1 2025"). Q1 2025 HIGHLIGHTS Opera

May 7, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2 (A

May 7, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of May 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant’s name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300 (Address of principal execut

May 7, 2025 EX-99.1

OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three months ended March 31, 2025 and 2024

Exhibit 99.1 OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Unaudited Condensed Interim Consolidated Financial Statements For the three months ended March 31, 2025 and 2024 Osisko Development Corp. Consolidated Statements of Financial Position As at March 31, 2025 and December 31 2024 (Unaudited) (Tabular amounts expressed in thousands of Canadian dollars) March 31, December 31, 2025

May 7, 2025 EX-99.3

FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE

Exhibit 99.3 FORM 52-109F2 CERTIFICATION OF INTERIM FILINGS FULL CERTIFICATE I, Sean Roosen, Chair of the Board and Chief Executive Officer of Osisko Development Corp., certify the following: 1. Review: I have reviewed the interim financial report and interim MD&A (together, the “interim filings”) of Osisko Development Corp. (the “issuer”) for the interim period ended March 31, 2025. 2. No misrepr

April 28, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

April 28, 2025 EX-99.1

Osisko Development Announces Optimized Feasibility Study for Permitted Cariboo Gold Project with C$943 Million After-Tax NPV5% and 22.1% IRR at US$2,400/oz Base Case Gold Price; at US$3,300/oz Spot Gold C$2.1 Billion After-Tax NPV5% and 38.0% IRR (Al

EXHIBIT 99.1 Osisko Development Announces Optimized Feasibility Study for Permitted Cariboo Gold Project with C$943 Million After-Tax NPV5% and 22.1% IRR at US$2,400/oz Base Case Gold Price; at US$3,300/oz Spot Gold C$2.1 Billion After-Tax NPV5% and 38.0% IRR (All dollar amounts are expressed in CAD dollars, unless stated otherwise) HIGHLIGHTS1 Robust returns with base case after-tax NPV5% of $943

April 21, 2025 LETTER

LETTER

April 21, 2025 Ryan Schedler Reporting Person Condire Management, LP 1717 McKinney Ave.

April 14, 2025 EX-99.1

Osisko Development Announces Supplemental Listing of Warrants

EXHIBIT 99.1 Osisko Development Announces Supplemental Listing of Warrants MONTREAL, April 14, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") is pleased to announce that its common share purchase warrants (the "Warrants") issued pursuant to private placements completed by the Company between October and November of 2024 will be liste

April 14, 2025 6-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-4136

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of April 2025 Commission File Number: 001-41369 Osisko Development Corp. (Translation of registrant's name into English) 1100 Avenue des Canadiens-de-Montréal, Suite 300, Montréal, Quebec H3B 2S2

March 31, 2025 EX-99.18

CONSENT OF EXPERT

Exhibit 99.18 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Vincent

March 31, 2025 EX-99.4

CERTIFICATIONS

Exhibit 99.4 CERTIFICATIONS I, Sean Roosen, certify that: 1. I have reviewed this annual report on Form 40-F of Osisko Development Corp.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respec

March 31, 2025 EX-99.28

CONSENT OF EXPERT

Exhibit 99.28 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Richard

March 31, 2025 EX-99.29

CONSENT OF EXPERT

Exhibit 99.29 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Daniel

March 31, 2025 EX-99.19

CONSENT OF EXPERT

Exhibit 99.19 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Jean-Fr

March 31, 2025 EX-99.20

CONSENT OF EXPERT

Exhibit 99.20 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Keith M

March 31, 2025 EX-99.9

CONSENT OF EXPERT

Exhibit 99.9 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Carl Pel

March 31, 2025 EX-99.2

OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Consolidated Financial Statements For the years ended December 31, 2024 and 2023

Exhibit 99.2 OSISKO DEVELOPMENT CORP. . . . . . . . . . . . . . . . . . . Consolidated Financial Statements For the years ended December 31, 2024 and 2023 Report of Independent Registered Public Accounting Firm To the Board of Directors and Shareholders of Osisko Development Corp. Opinion on the Financial Statements We have audited the accompanying consolidated statements of financial position of

March 31, 2025 EX-99.27

CONSENT OF EXPERT

Exhibit 99.27 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Alan J.

March 31, 2025 EX-99.25

CONSENT OF EXPERT

Exhibit 99.25 CONSENT OF EXPERT I, Laurentius Verburg, P. Geo. consent to the following in connection with the Annual Report on Form 40-F for the year ended December 31, 2024 (“Annual Report”) of Osisko Development Corp.: (i) the quotation, inclusion or summary of those portions prepared by me of the technical report entitled Feasibility Study for the Cariboo Gold Project, District of Wells, Briti

March 31, 2025 EX-99.8

Consent of Independent Registered Public Accounting Firm

Exhibit 99.8 Consent of Independent Registered Public Accounting Firm We hereby consent to the incorporation by reference in this Annual Report on Form 40-F for the year ended December 31, 2024 of Osisko Development Corp. of our report dated March 28, 2025, relating to the consolidated financial statements, which appears in Exhibit 99.2 incorporated by reference in this Annual Report on Form 40-F.

March 31, 2025 EX-99.1

ANNUAL INFORMATION FORM FOR THE FISCAL YEAR ENDED DECEMBER 31, 2024 DATED AS OF MARCH 28, 2025

Table of Contents Exhibit 99.1 ANNUAL INFORMATION FORM FOR THE FISCAL YEAR ENDED DECEMBER 31, 2024 DATED AS OF MARCH 28, 2025 Table of Contents TABLE OF CONTENTS GENERAL MATTERS 1 CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION 1 CAUTIONARY NOTE TO U.S. INVESTORS REGARDING PREPARATION OF FINANCIAL INFORMATION 2 CAUTIONARY NOTE TO U.S. INVESTORS REGARDING THE USE OF MINERAL RESERVE AND M

March 31, 2025 EX-97

OSISKO DEVELOPMENT CORP. CLAWBACK POLICY

Exhibit 97 OSISKO DEVELOPMENT CORP. CLAWBACK POLICY A.Application of Policy This Clawback Policy (this “Policy”) applies in the event of any restatement (“Restatement”) of the financial results of Osisko Development Corp. (the “Corporation”) due to its material non-compliance with financial reporting requirements under applicable securities laws. This Policy does not apply to restatements that are

March 31, 2025 EX-99.12

CONSENT OF EXPERT

Exhibit 99.12 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Katheri

March 31, 2025 EX-99.3

OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and twelve months ended December 31, 2024

Table of Contents Exhibit 99.3 OSISKO DEVELOPMENT CORP. Management's Discussion and Analysis For the three and twelve months ended December 31, 2024 The following management discussion and analysis ("MD&A") of the operations and financial position of Osisko Development Corp. and its subsidiaries ("Osisko Development" or the "Company") for the three and twelve months ended December 31, 2024 ("Q4 20

March 31, 2025 EX-99.17

CONSENT OF EXPERT

Exhibit 99.17 CONSENT OF EXPERT The undersigned hereby consents to the use of their report, and the information derived therefrom, as well as the reference to their name, in each case where used or incorporated by reference in the Annual Report on Form 40-F of Osisko Development Corp. being filed with the United States Securities and Exchange Commission, and any amendments thereto. By: /s/ Éric Le

March 31, 2025 EX-99.1

Osisko Development Reports Fourth Quarter and Year-End 2024 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise)

EXHIBIT 99.1 Osisko Development Reports Fourth Quarter and Year-End 2024 Results (All dollar amounts are expressed in Canadian dollars, unless stated otherwise) MONTREAL, March 28, 2025 (GLOBE NEWSWIRE) - Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") reports its financial and operating results for the three and twelve months ended December 31, 2024 ("Q4 20

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