Osisko Intersects 138 Metres Averaging 1.45% Cu in South Extension at GaspéIncludes 64.5 Metres Averaging 2.70% Cu MONTREAL, Nov. 20, 2025 (GLOBE NEWSWIRE) -- Osisko Metals Incorporated (the “ Company or " Osisko Metals ") ( TSX: OM ; OTCQX: OMZNF ; FRANKFURT: 0B51 ) is pleased to announce new drill results from the Gaspé Copper Project, located in the Gaspé Peninsula of Eastern Québec. Osisko Metals CEO Robert Wares commented: “These latest results continue to confirm significant higher-grade mineralization in the southern extension, with hole 30-1136 returning 64.5 metres averaging 2.70% Cu. We remain highly confident about the growth of our project and look forward to the updated Mineral Resource Estimate in early 2026.” New analytical results are presented below (see Table 1), including 21 mineralized intercepts from eight new drill holes. Infill intercepts are located inside the 2024 MRE model ( see November 14, 2024 news release ), and are focused on upgrading inferred mineral resources to measured or indicated categories, as applicable. Expansion intercepts are located outside the 2024 MRE model and may potentially lead to additional resources that will be classified appropriately within the next MRE update. Some of the reported intercepts have contiguous shallower infill as well as deeper expansion (noted on Table 1 below as “Both”). Maps showing hole locations are available at www.osiskometals.com . Highlights: Drill hole 30-1136 284.5 metres averaging 0.41% Cu (0.43% CuEq – expansion) 138.0 metres averaging 1.45% Cu (1.52% CuEq – expansion), including 64.5 metres averaging 2.70% Cu (2.82% CuEq – expansion) Drill hole 30-1120 598.5 metres averaging 0.28% Cu (0.37% CuEq – infill and expansion) Drill hole 30-1129 881.0 metres averaging 0.22% Cu (0.30% CuEq – infill and expansion) Drill hole 30-1133 550.5 metres averaging 0.28% Cu (0.36% CuEq – infill and expansion) Drill hole 30-1134 309.0 metres averaging 0.17% Cu (0.27% CuEq – infill and expansion) 228.5 metres averaging 0.41% Cu (0.52% CuEq – expansion) Drill hole 30-1138 685.8 metres averaging 0.27% Cu (0.35% CuEq – infill) Drill hole 30-1139 873.0 metres averaging 0.23% Cu (0.29% CuEq – infill) Drill hole 30-1140 105.0 metres averaging 0.43% Cu (0.50% CuEq – infill) Table 1: Infill and Expansion Drilling Results DDH No. From (m) To (m) Length (m) Cu % Ag g/t Mo % CuEq* % Type** 30-1120 143.0 415.5 272.5 0.22 1.84 0.005 0.25 Infill And 541.5 1140.0 598.5 0.28 1.60 0.023 0.37 Both (including) 541.5 784.1 242.6 0.22 1.60 0.023 0.32 Infill (including) 784.1 1140.0 355.9 0.32 1.60 0.024 0.42 Expansion 30-1129 16.9 897.9 881.0 0.22 4.32 0.014 0.30 Both (including) 16.9 645.9 629.0 0.23 1.61 0.011 0.28 Infill (including) 645.9 897.9 252.0 0.20 2.08 0.023 0.30 Expansion And 1013.6 1063.5 49.9 0.21 2.70 0.009 0.25 Expansion 30-1133 26.0 51.0 25.0 0.24 1.74 0.25 Infill And 205.5 226.5 21.0 0.11 1.31 0.009 0.15 Infill And 247.5 294.0 46.5 0.12 1.08 0.011 0.17 Infill And 310.5 861.0 550.5 0.28 1.89 0.018 0.36 Both (including) 310.5 744.0 433.5 0.28 1.79 0.018 0.36 Infill (including) 744.0 861.0 117.0 0.3 2.27 0.019 0.38 Expansion 30-1134 46.5 339.0 292.5 0.17 0.81 0.008 0.20 Infill And 393.0 702.0 309.0 0.17 0.74 0.027 0.27 Both (including) 393.0 577.1 184.1 0.18 0.84 0.021 0.26 Infill (including) 577.1 702.0 124.9 0.14 0.60 0.037 0.28 Expansion And 780.0 1008.5 228.5 0.41 1.67 0.027 0.52 Expansion 30-1136 17.0 301.5 284.5 0.41 2.83 0.43 Expansion (including) 151.5 169.5 18.0 1.35 7.40 1.42 Expansion And 376.5 514.5 138.0 1.45 10.8 1.52 Expansion (including) 379.5 444.0 64.5 2.70 19.0 2.82 Expansion 30-1138 29.7 715.5 685.8 0.27 1.47 0.018 0.35 Infill 30-1139 7.0 26.0 19.0 0.35 2.59 0.37 Infill And 78.0 951.0 873.0 0.23 1.78 0.011 0.29 Infill 30-1140 5.5 61.0 55.5 0.29 2.08 0.30 Infill And 124.5 187.5 63.0 0.16 1.90 0.011 0.22 Infill And 355.5 460.5 105.0 0.43 3.08 0.012 0.50 Infill And 493.8 687.0 193.2 0.16 1.10 0.021 0.25 Both (including) 493.8 609.0 115.2 0.16 1.17 0.026 0.27 Infill (including) 609.0 687.0 78.0 0.16 1.01 0.014 0.22 Expansion And 787.3 856.5 69.2 0.22 1.33 0.039 0.37 Expansion * See explanatory notes below on copper equivalent values and Quality Assurance/Quality Controls. ** “Both” indicates drill holes that have contiguous shallower infill as well as deeper expansion intercepts. Discussion Drill hole 30-1120, located on top of Copper Mountain near the centre of the 2024 MRE model, cut two significant mineralized intervals including 272.5 metres averaging 0.22 % Cu and 1.84 g/t Ag, followed by 598.5 metres averaging 0.28% Cu, 1.60 g/t Ag and 0.023% Mo, extending mineralization in this area to a vertical depth of 1140 metres. Drill hole 30-1129, located on the western flank of Copper Mountain, cut two mineralized intervals including 881.0 metres averaging 0.22 % Cu and 4.32 g/t Ag and 0.014% Mo (which includes 200 metres of depth expansion), extending mineralization in this area to a vertical depth of 897.9 metres. Drill hole 30-1133, lo