Mr. Don Njegovan reports

OSISKO INTERSECTS 314 METRES AVERAGING 0.44% CU AT GASPE

Osisko Metals Inc. has released new analytical results from the continuing 2026 drill program at the Gaspe copper project, located in the Gaspe Peninsula of eastern Quebec. Results are presented below (see Table 1), and include 38 mineralized intercepts from 15 drill holes. Reported infill intercepts are located within the 2026 MRE (mineral resource estimate) model (see April 14, 2026, news release ), focused on upgrading inferred mineral resources to measured or indicated categories, as applicable. Expansion intercepts are located outside the 2026 MRE model and comprise either: (i) in-pit expansion, which offers potential to convert in-pit waste into additional resources within the 2026 MRE Whittle pit; or (ii) out-of-pit expansion, consisting of mineralization located outside the 2026 MRE Whittle pit, which may potentially lead to the definition of new resources. Some of the reported intercepts may have contiguous shallower infill as well as deeper in-pit expansion (noted as "Both"). Maps showing hole locations are available on Osisko Metals' website.

Osisko Metals chief executive officer Robert Wares commented: "Today's results, particularly drill holes 30-1270 and 30-1272, show once again strong results from the southern end of the 2026 MRE model. Furthermore, drill hole 30-1260, which is the most southerly hole drilled to date at Needle Mountain (out-of-pit expansion), located approximately 400 metres southwest of the current 2026 MRE pit boundary, returned 121 metres averaging 0.42 per cent Cu at the level of the B and C zones, indicating the system continues to be well mineralized and open to the south."

Highlights:

• 314.0 metres averaging 0.44 per cent Cu (infill) in DDH 30-1272; includes 9.0 metres averaging 3.23 per cent Cu and 16.7 grams per tonne silver;
• 240.5 metres averaging 0.44 per cent Cu (infill) in DDH 30-1270;
• 552.5 metres averaging 0.30 per cent Cu (infill) in DDH 30-1269;
• 142.6 metres averaging 0.34 per cent Cu (infill) in DDH 30-1274;
• 121.5 metres averaging 0.42 per cent Cu (out-of-pit expansion) in DDH 30-1260;
• 87.5 metres averaging 0.48 per cent Cu (out-of-pit expansion) in DDH 30-1268; includes 10.7 metres averaging 1.98 per cent Cu and 9.0 g/t Ag;
• 85.5 metres averaging 0.42 per cent Cu (out-of-pit expansion) in DDH 30-1265.

Additional comments

Drill holes 30-1260 and 30-1268 are located on the north flank of Needle Mountain near its peak, with 30-1260 being the most southerly hole drilled to date on Needle Mountain. Hole 30-1260 was a vertical hole that intersected 121.5 metres averaging 0.42 per cent Cu and 2.39 g/t Ag at the level of the B and C zone skarns, including the intervening porcellanites. Drill hole 30-1268 is a westerly inclined hole that intersected 87.5 metres averaging 0.48 per cent Cu and 2.71 g/t Ag, also at the level of the B and C zone skarns. Both holes indicate that the mineralized system at Needle Mountain remains open to the south.

Drill hole 30-1266 is a westerly inclined hole located along the northeastern margin of the Needle Mountain pit. It intersected two short intervals of mineralization, including 33.0 metres averaging 0.41 per cent Cu and 2.63 g/t Ag.

Drill hole 30-1265 is a vertical hole located just south of the southern limit of the 2026 MRE model. It intersected four intervals of mineralization, 12.4 to 85.5 metres long, averaging 0.27 to 0.83 per cent Cu and 2.43 to 7.30 g/t Ag, the last interval representing a significant out-of-pit expansion.

Drill holes 30-1262, 30-1270 and 30-1272 are all infill holes located near the southern margin of the 2026 MRE model. Hole 30-1262 is westerly inclined that expanded the mineralized envelope to the west, while 30-1270 and 30-1272 drilled through pillars of both the B zone and C zone underground workings, returning continuous well-mineralized intervals of 240.5 and 314.0 metres, respectively, averaging 0.44 per cent Cu.

Drill holes 30-1261, 30-1263, 30-1264, 30-1267, 30-1269, 30-1271 and 30-1274 are all vertical to near-vertical infill holes located on the southern flank of Copper Mountain. All returned multiple mineralized intervals that graded in a range of 0.12 per cent to 0.40 per cent Cu, all within values anticipated from the 2026 MRE model.

Mineralization at Gaspe Copper is of porphyry copper/skarn type and occurs as disseminations and stockworks of chalcopyrite with pyrite or pyrrhotite and minor bornite and molybdenite. One pro-grade and at least five retrograde vein/stockwork mineralizing events have been recognized at Copper Mountain, which overprint earlier stratiform, carbonate replacement skarn and porcellanite-hosted mineralization throughout the Gaspe Copper system. Porcellanite is a historical mining term used to describe bleached, pale green to white potassic-altered hornfels. Subvertical stockwork mineralization dominates at Copper Mountain whereas pro-grade bedding-parallel mineralization, which is mostly stratigraphically controlled, dominates in the area of lower Copper Mountain, Needle Mountain, Needle East and Copper Brook. High molybdenum grades (up to 0.5 per cent Mo) were locally obtained in both the C zone and E zone skarns away from Copper Mountain.

The 2022 to 2024 Osisko Metals drill programs were focused on defining open-pit resources within the Copper Mountain stockwork mineralization (see May 6, 2024, MRE press release). Extending the resource model south of Copper Mountain into the poorly drilled pro-grade skarn/porcellanite portion of the system subsequently led to a significantly increased resource, mostly in the inferred category (see Nov. 14, 2024, MRE press release), and additional drilling in 2025 led to an additional significant increase in resources, mostly in the measured and indicated categories (see April 14, 2026, MRE press release).

The current drill program is designed to convert the bulk of the remaining 2026 MRE inferred resources to measured and indicated categories as well as test the expansion of the overall resource laterally to the west, and to the south/southwest toward Needle East and Needle Mountain, respectively.

Explanatory note regarding copper equivalent grades

Copper equivalent (CuEq) grades are presented for illustrative purposes only to express the combined value of copper, molybdenum and silver as a single copper grade. CuEq grades are calculated using long-term metal prices of $4.50 (U.S.) per pound copper, $20 (U.S.) per pound molybdenum and $45 (U.S.) per pound ounce silver and incorporate assumptions for metallurgical recoveries, payable metal factors, smelting and refining charges, transportation costs and royalties. Hence, the CuEq calculation is essentially based on net smelter return (NSR) values. NSR for each metal is estimated by applying metallurgical recoveries, payable factors, metal prices, and applicable smelting, refining, transportation and penalty charges to the in situ metal grades. CuEq grades are derived using a linear regression relationship established between copper grade and copper NSR and then calculated by substituting total NSR (Cu plus Mo plus Ag) for copper NSR in the regression equation. The simplified formula is expressed as CuEq (per cent) equal to Cu (per cent) plus 3.40327 multiplied by Mo (per cent) plus 0.00008 multiplied by Ag (g/t).

Qualified person

The scientific and technical content of this news release has been reviewed and approved by Bernard-Olivier Martel, PGeo (OGQ No. 492), an independent qualified person as defined by National Instrument 43-101, Standards of Disclosure for Mineral Projects.

Quality assurance/quality control

Mineralized intervals reported herein are calculated using an average 0.12-per-cent-copper-equivalent lower cut-off over contiguous 20-metre intersections (shorter intervals as the case may be at the upper and lower limits of reported intervals). Intervals of 10 metres or less are generally not reported unless considered material. True widths are estimated at 80 per cent to 90 per cent of the reported core length 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 drilled in HQ or NQ diameter and 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. Sample preparation details (code PREP-31DH) are available on the ALS Canada website. Pulps are analyzed at the ALS Canada facility in North Vancouver, B.C. All samples are analyzed by four-acid digestion followed by both ICP-AES and ICP-MS for Cu, Mo and Ag.

About Osisko Metals Inc.

Osisko Metals 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-per-cent interest in the past-producing Gaspe copper mine from Glencore Canada Corp. in July, 2023. The Gaspe copper mine site is located near Murdochville in Quebec's Gaspe peninsula. The company is currently focused on resource expansion of the Gaspe copper deposits, with current pit-constrained measured and indicated mineral resources of 1.83 billion tonnes averaging 0.32 per cent CuEq and inferred mineral resources of 239 million tonnes averaging 0.46 per cent CuEq (in compliance with NI 43-101).

For more information, see Osisko Metals' April 14, 2026, news release entitled "Osisko Metals Announces Significant Increase in Mineral Resource at Gaspe Copper." Gaspe Copper hosts the largest undeveloped copper resource in eastern North America, strategically located near existing infrastructure in the mining-friendly province of Quebec.

In addition to the Gaspe copper project, the company is working with Appian Capital Advisory LLP through the Pine Point Mining Ltd. 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 million tonnes averaging 5.52 per cent zinc equivalent and inferred mineral resources of 8.3 million tonnes averaging 5.64 per cent 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 per cent 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 kilometres of viable haul roads.

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