Mr. Sean Roosen reports

OSISKO GOLD COMPLETES NAME CHANGE FROM OSISKO DEVELOPMENT

Osisko Gold Group Inc. has completed its previously announced name change to Osisko Gold Group Inc. from Osisko Development Corp., effective July 14, 2026, following receipt of shareholder approval at its annual and special meeting of shareholders held on June 23, 2026, and receipt of other applicable regulatory approvals.

The Osisko Gold common shares are expected to commence trading under its new name and stock ticker symbol OGG on the TSX Venture Exchange and the New York Stock Exchange (NYSE) at market open on July 20, 2026.

In addition, the trading symbols for the company's common share purchase warrants are also expected to change effective at market open on July 20, 2026: (i) warrants trading under ODVWZ on the Nasdaq Stock Market and ODV.WT.U on the TSX-V will change to OGGWZ and OGG.WT.U, respectively; and (ii) warrants trading on the TSX-V under ODV.WT.A and ODV.WT.V will change to OGG.WT.A and OGG.WT.V, respectively.

In connection with the name and stock ticker symbol changes of the company's listed securities, the Cusips and ISINs of the company's securities will change as well. For the company's common shares, the Cusip and ISIN will be changed to 68827X105 and CA68827X1050, respectively. In addition, the following new Cusip and ISIN numbers have been assigned to the warrants of the company: (i) OGG.WT.A: Cusip 68827X139 and ISIN CA68827X1399; (ii) OGG.WT.U (TSX-V) and OGGWZ (Nasdaq): Cusip 68827X113 and ISIN CA68827X1134; and (iii) OGG.WT.V: Cusip 68827X121 and ISIN CA68827X1217.

There are no anticipated interruptions to the company's trading activities in connection with the name change. Certificates and direct registration system (DRS) statements representing common shares and purchase warrants of the company will not be affected by the name change and securityholders will not be required to exchange their securities or take any other action. Securityholders holding physical share certificates of the company may request replacement certificates from the company's transfer agent; however, new certificates are not required and will not be automatically issued.

The name change reflects the company's evolution toward a primary gold and precious-metals-focused asset base in North America, anchored by the continued derisking and advancement of its fully permitted Cariboo gold project in British Columbia, Canada. In connection with the name change, the company has also rebranded its website.

About Osisko Gold Group Inc.

Osisko Gold Group is a continental North American gold development company focused on past-producing mining camps with district-scale potential. The company's objective is to become an intermediate gold producer through the development of its flagship, fully permitted, 100-per-cent-owned Cariboo gold project, located in central British Columbia, Canada. Its project pipeline is complemented by the Tintic project, located in the historic East Tintic mining district in Utah, U.S., a brownfield property with significant exploration potential, extensive historical mining data and access to established infrastructure. Osisko Gold is focused on developing long-life mining assets in mining-friendly jurisdictions while maintaining a disciplined approach to capital allocation, development risk management and mineral inventory growth.

We seek Safe Harbor.