Osisko Metals Intersects 300 Metres Averaging 0.39% Copper at Gaspé Copper Project

Initial Drilling Results Extend Deposit to the South and at Depth

Osisko Metals Gaspé Copper Project

MONTREAL, April 14, 2025 (GLOBE NEWSWIRE) — Osisko Metals Incorporated (the “Company or “Osisko Metals“) (TSX-V: OM; OTCQX: OMZNF; FRANKFURT: 0B51) is pleased to announce initial drilling results from the 2025 drilling program at the Gaspé Copper Project, located in the Gaspé Peninsula of Eastern Québec. Results for five holes are reported below, collared at the southern margin of the mineralized deposit as defined in the 2024 Mineral Resource Estimate (MRE, see attached map and November 14, 2024 news release).

Highlights (see Table 1 below):

• Drill hole 30-1059 intersected 300.0 metres grading 0.39% Cu and 3.17 g/t Ag within the 2024 MRE model where there was limited historical data.
• Drill hole 30-1060 intersected 220.5 metres grading 0.29% Cu and 2.09 g/t Ag within the 2024 MRE model, as well as 211.0 metres grading 0.42% Cu and 2.27 g/t Ag at depth below the 2024 MRE model, extending mineralization to a vertical depth of 598 metres.
• Drill hole 30-1063 intersected 109.5 metres grading 0.32% Cu and 2.52 g/t Ag within the 2024 MRE model, as well as 61.5 metres grading 0.33% Cu and 2.60 g/t Ag, and 43.5 metres grading 0.48% Cu and 3.20 g/t Ag at depth below the 2024 MRE model, extending mineralization to a vertical depth of 678 metres.
• Drill hole 30-1069 intersected 237.0 metres grading 0.32% Cu and 2.46 g/t Ag within the 2024 MRE model, as well as 148.8 metres grading 0.63% Cu and 4.40 g/t Ag at depth below the 2024 MRE model, extending mineralization to a vertical depth of 528 metres.
• Drill hole 30-947, an un-assayed historical hole located 110 metres south of the 2024 MRE model, was stockpiled on site and the core recovered and assayed, yielding five significant intersections, including 82.0 metres grading 0.31% Cu and 2.55 g/t Ag. These results indicate that the deposit is open to the south.

Robert Wares, Osisko Metals CEO, commented: “We are very pleased with these new drill results at Gaspé, which have exceeded our expectations. All holes intersected significant disseminated mineralization within the volume of the 2024 MRE model, and new mineralization has been added at depth well below the base of the 2024 MRE model, which was constrained to the lower contact of the C Zone skarn horizon. Drill core from historical hole 30-947 was also recovered and assayed, yielding positive results and indicating that the deposit extends laterally 110 metres south of the 2024 MRE model and remains open in that direction. This is an excellent start to the 2025 drill program, and we look forward to a regular flow of results from our 110,000-metre program as we confirm our large existing copper resource, and aim to expand it at depth, to the south and to the west towards Needle Mountain.”

Table 1: Drill Hole Mineralized Intervals; intersections indicated in bold occur outside the November 2024 MRE model. See attached map for drill hole locations.

All drill holes were drilled sub-vertically into the Gaspé Copper altered calcareous stratigraphy that dips 20 to 25 degrees to the north; true widths are estimated at 90-92% of reported widths. The L1 (C Zone) the L2 (E Zone) skarn/marble horizons were intersected in all holes, as well as intervening porcellanites (potassic-altered hornfels) that host the bulk of the disseminated copper mineralization.

Mineralization occurs as disseminations and veinlets of chalcopyrite and is mostly stratigraphically controlled in the area of Needle Mountain, Needle East and Copper Brook. As expected, no significant molybdenum mineralization was encountered in porcellanites in the latter areas, but high grades (up to 0.4% Mo) were locally obtained in both the C Zone and E Zone skarns. The bulk of the molybdenum mineralization occurs in the stockworks further north at Copper Mountain, where true porphyry copper-style stockwork mineralization occurs, forming a distinct secondary mineralized zone that is characterized by widespread, continuous copper-molybdenum mineralization radiating from the central source of hydrothermal fluids, i.e. the Copper Mountain porphyry intrusion. At least five vein/stockwork mineralizing events have been recognized at Copper Mountain, which overprint earlier skarn/porcellanite-hosted mineralization throughout the Gaspé Copper system. The 2022 to 2024 Osisko Metals drill programs were focused on defining open-pit resources within the Copper Mountain stockwork mineralization, leading to the May 2024 MRE (see May 6, 2024 press release). Extending the resource model south of Copper Mountain into the poorly-drilled primary skarn/porcellanite portion of the system subsequently led to a significantly increased resource, mostly in the Inferred category (see November 14, 2024 press release).

The 2025 drill program is primarily designed to convert the November 2024 MRE to Measured and Indicated categories, as well as test the expansion of the system deeper into the stratigraphy and laterally to the south and southwest towards Needle East and Needle Mountain respectively.

Qualified Person

Mr. Bernard-Olivier Martel, P. Geo., an independent consultant, is the Qualified Person responsible for the technical data reported in this news release and he is a Professional Geologist registered in the Province of Quebec.

Quality Assurance / Quality Control

Mineralized intervals reported herein are calculated using an average 0.12% copper lower cutoff over contiguous 20-metre intersections (shorter intervals as the case may be at the upper and lower limits of reported intervals).

Osisko Metals adheres to a strict QA/QC program for core handling, sampling, sample transportation and analyses, including insertion of blanks and standards in the sample stream. Drill core is securely transported to its core processing facility on site, where it is logged, cut and sampled. Samples selected for assay are sealed and shipped to ALS Canada Ltd.’s preparation facility in Sudbury. Pulps are analyzed at the ALS Canada Ltd. facility in North Vancouver, BC. All samples are analyzed by four acid digestion followed by both ICP-AES and ICP-MS for copper, molybdenum and silver.

About Osisko Metals

Osisko Metals Incorporated is a Canadian exploration and development company creating value in the critical metals sector, with a focus on copper and zinc. The Company acquired a 100% interest in the past-producing Gaspé Copper mine from Glencore Canada Corporation in July 2023. The Gaspé Copper mine is located near Murdochville in Québec‘s Gaspé Peninsula. The Company is currently focused on resource expansion of the Gaspé Copper system, with current Indicated Mineral Resources of 824 Mt grading 0.34% CuEq and Inferred Mineral Resources of 670 Mt grading 0.38% CuEq (in compliance with NI 43-101). For more information, see Osisko Metals’ November 14, 2024 news release entitled “Osisko Metals Announces Significant Increase in Mineral Resource at Gaspé Copper“. Gaspé Copper hosts the largest undeveloped copper resource in eastern North America, strategically located near existing infrastructure in the mining-friendly province of Québec.

In addition to the Gaspé Copper project, the Company is working with Appian Capital Advisory LLP through the Pine Point Mining Limited joint venture to advance one of Canada‘s largest past-producing zinc mining camps, the Pine Point project, located in the Northwest Territories. The current mineral resource estimate for the Pine Point project consists of Indicated Mineral Resources of 49.5 Mt at 5.52% ZnEq and Inferred Mineral Resources of 8.3 Mt at 5.64% ZnEq (in compliance with NI 43-101). For more information, see Osisko Metals‘ June 25, 2024 news release entitled “Osisko Metals releases Pine Point mineral resource estimate: 49.5 million tonnes of indicated resources at 5.52% ZnEq”. The Pine Point project is located on the south shore of Great Slave Lake, Northwest Territories, close to infrastructure, with paved road access, an electrical substation and 100 kilometers of viable haul roads.

For further information on this news release, visit www.osiskometals.com or contact:

Don Njegovan, President Email: info@osiskometals.com

Cautionary Statement on Forward-Looking Information

This news release contains “forward-looking information” within the meaning of applicable Canadian securities legislation based on expectations, estimates and projections as at the date of this news release. Any statement that involves predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often, but not always, using phrases such as “expects”, or “does not expect”, “is expected”, “interpreted”, management’s view”, “anticipates” or “does not anticipate”, “plans”, “budget”, “scheduled”, “forecasts”, “estimates”, “potential”, “feasibility”, “believes” or “intends” or variations of such words and phrases or stating that certain actions, events or results “may” or “could”, “would”, “might” or “will” be taken, occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This news release contains forward-looking information pertaining to, among other things: the tax treatment of the FT Units; the timing of incurring the Qualifying Expenditures and the renunciation of the Qualifying Expenditures; the ability to advance Gaspé Copper to a construction decision (if at all); the ability to increase the Company’s trading liquidity and enhance its capital markets presence; the potential re-rating of the Company; the ability for the Company to unlock the full potential of its assets and achieve success; the ability for the Company to create value for its shareholders; the advancement of the Pine Point project; the anticipated resource expansion of the Gaspé Copper system and Gaspé Copper hosting the largest undeveloped copper resource in eastern North America.

Forward-looking information is not a guarantee of future performance and is based upon a number of estimates and assumptions of management, in light of management’s experience and perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances, including, without limitation, assumptions about: the ability of exploration results, including drilling, to accurately predict mineralization; errors in geological modelling; insufficient data; equity and debt capital markets; future spot prices of copper and zinc; the timing and results of exploration and drilling programs; the accuracy of mineral resource estimates; production costs; political and regulatory stability; the receipt of governmental and third party approvals; licenses and permits being received on favourable terms; sustained labour stability; stability in financial and capital markets; availability of mining equipment and positive relations with local communities and groups. Forward-looking information involves risks, uncertainties and other factors that could cause actual events, results, performance, prospects and opportunities to differ materially from those expressed or implied by such forward-looking information. Factors that could cause actual results to differ materially from such forward-looking information are set out in the Company’s public disclosure record on SEDAR+ (www.sedarplus.ca) under Osisko Metals’ issuer profile. Although the Company believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. The Company disclaims any intention or obligation to update or revise any forward- looking information, whether as a result of new information, future events or otherwise, other than as required by law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accept responsibility for the adequacy or accuracy of this news release. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.

A photo accompanying this announcement is available at https://www.globenewswire.com/NewsRoom/AttachmentNg/86f64a14-ab80-44b9-804a-0b997e5fc82e