Principal Project: Cu-Ag-Au Porphyry-Skarn in Northern New Brunswick

Defined Target Area Has Alteration Footprint Larger than Gaspé Copper Project

Spin-Out Osisko Critical Minerals Corporation to Commence Exploration Following Completion of the Transaction

Osisko Metals Incorporated (TSX: OM) (OTCQX: OMZNF) (FRANKFURT: 0B51) is pleased to announce its intentions to create a new mineral exploration company to be named “Osisko Critical Minerals Corporation” which will be led by John Burzynski as Chief Executive Officer. OCMC is designed to unlock the value of Osisko Metals non-core projects by transferring a portfolio of mineral exploration properties located in New Brunswick into OCMC, a dedicated, standalone vehicle.

Incoming CEO John Burzynski commented: “We are excited by the prospect of this new copper and critical minerals exploration company and the assets it brings forward. New Brunswick has been home to major metal deposits in the past, and we believe there is excellent potential for defining a significant mineralized bulk-tonnage porphyry-skarn deposit on OCMC’s assets. Historically there has been no exploration for these systems in northern New Brunswick, despite a near-identical geological setting and the relatively close proximity to the Gaspé Copper Project. Much as the Osisko companies redefined gold exploration in Québec with our past work at Canadian Malartic and at Windfall, we believe there is significant untested potential on the assets that will be transferred to OCMC, which could lead to the discovery of new copper deposits in New Brunswick. Plans for OCMC will include an aggressive exploration program and drilling, planned to start following the conclusion and financing of the transaction.”

Creation of OCMC

In connection with its creation, the Company intends to explore financing alternatives, with Osisko Metals to retain a minority interest in OCMC following completion of any such financing. An overview of the Properties is included below. Additional details will be provided as matters progress.

The completion of the transaction and the exact form and consideration of vending the Properties into OCMC are subject to a number of conditions, including the completion of legal and tax structuring analyses; completion of financial analysis; determination of the structure and amount of funding of OCMC; determination of final details of the transaction; settlement of the board of directors and management team for OCMC; and required regulatory approvals. There can be no assurance that any securities of OCMC will be listed on any stock exchange.

Benefits of the Transaction

The transaction will provide shareholders of Osisko Metals with an indirect interest in OCMC through the Company’s retained ownership interest in OCMC, which will allow the capital markets to ascribe value to the Properties independently of Osisko Metals core property assets.

The proposed transaction will enable Osisko Metals to focus on advancing its flagship project, the past-producing Gaspé Copper mine located near Murdochville in Québec’s Gaspé Peninsula. The Company is currently completing resource expansion work on the Gaspé Copper Project, which hosts current pit-constrained Measured and Indicated Mineral Resources of 1.83 Bt averaging 0.32% CuEq and Inferred Mineral Resources of 239 Mt averaging 0.46% CuEq. For more information see the technical report prepared in accordance with NI 43-101 titled “NI 43-101 Technical Report on the Gaspé Copper Project with an Updated Mineral Resource Estimate for the Copper Mountain Deposit, Québec, Canada” dated May 28, 2026 (with an effective date of January 17, 2026) available on SEDAR+ (www.sedarplus.ca) under Osisko Metals’ issuer profile.

OCMC Highlights

The Properties comprise an aggregate of 2,972 mineral claim units (approximately 645 square kilometres) staked by the Company and claims which Osisko Metals has an option to acquire pursuant to three separate option agreements (the “Option Agreements”, entered into on January 9, 2026; April 20, 2026; and September 9, 2026 respectively). In connection with the transaction, the Option Agreements will be assigned to OCMC in exchange for shares of OCMC. The Properties include several large-scale mineral exploration targets prospective for copper, silver and gold, underlain by highly prospective geology similar in context to the nearby Gaspé Copper Project.

NB Copper Project

The NB Copper Project located in northern New Brunswick represents a compelling new copper exploration opportunity in a proven mining jurisdiction and is readily accessible via paved highways and gravel roads. The project area is situated on Crown land facilitating cost-effective exploration and permitting activities.

Geologically, the project lies within the Popelogan–Victoria Arc, immediately south of the Gaspé Belt. Multiple Devonian porphyritic intrusive phases of granodiorite characterize this regional tectonic setting, and porphyry emplaced into sedimentary, felsic volcanic, and mafic volcanic host rocks – geological conditions analogous to those observed at the Gaspé Copper Project.

Historical exploration efforts in the area focused primarily on identifying high-grade skarn-style mineralization and were generally limited in scale, with only sparse shallow drilling. No comprehensive, modern exploration program has been conducted to assess the potential for large-scale, low-grade bulk-tonnage copper systems like the mineralization model currently being advanced at the Gaspé Copper Project.

Past drilling intersected multiple copper-bearing zones and skarn mineralization, however, exploration and drilling were largely confined to near-surface showings. Mineralization and skarn/porcellanite alteration has been identified across multiple geological units, extending over an interpreted area of nominally 5 kilometres x 2 kilometres, similar to the Copper Brook alteration aureole which characterizes the Gaspé Copper deposit. The property also hosts 21 additional porphyry intrusions that have never been evaluated for their bulk-tonnage copper potential.

Highlights

• The NB Copper Project presents a large exploration target that has not been systematically drill-tested and hosts significant potential for bulk tonnage deposits similar to the Gaspé Copper Project;
• Large land package (430 square kilometres);
• Devonian calc-alkaline porphyries intruded into Siluro-Devonian calcareous pelites and limestones (analogue to Gaspé Copper Project setting);
• Previous work has defined a large (minimum 5 kilometre x 2 kilometre) near-surface porcellanite/skarn alteration zone: a hydrothermal system larger in scale than the Gaspé Copper Project (3.5 kilometre x 2.5 kilometre), with local near-surface and surface copper mineralization;
• Sparse historical drilling focused on exploring for near-surface high-grade copper skarn mineralization (less than 200 metres deep). Only two deeper (500 metres – 600 metres) holes have been drilled, both showing skarn/porcellanite alteration from top to bottom, similar to that found at Gaspé Copper, with anomalous copper-gold mineralization near surface where analyses were made.

Bathurst Mining Camp

The main assets within the Bathurst Mining Camp holdings include the Key Anacon and Gilmour South Mineral Resource (Table 1) as well as the Mount Fronsac occurrence. The Key Anacon mineral resource estimate was completed in 2019 and hosts indicated mineral resources of 1.96 Mt averaging 5.77% zinc, 2.38% lead, 0.22% copper and 68.9 g/t silver (9.00% ZnEq) and inferred mineral resources of 3.85 Mt averaging 5.34% zinc, 1.49% lead, 0.32% copper and 47.7 g/t silver (7.96% ZnEq).

Table 1: For more information see the technical report prepared in accordance with NI 43-101 titled “NI 43-101 Maiden Resource Estimate for the Bathurst Mining Camp, New Brunswick, Canada” dated April 4, 2019 (with an effective date of February 20, 2019) available on SEDAR+ (www.sedarplus.ca) under Osisko Metals’ issuer profile.

The Mount Fronsac deposit contains an historical, non-NI 43-101 compliant, unclassified mineral resource estimate of 1.26 million tonnes averaging 7.65 % Zn, 2.18 % Pb, 0.14% Cu, 40.3 g/t Ag, and 0.40 g/t Au.

Additional Information

There is no certainty that the transaction will be completed on the terms proposed or at all. The board of directors of Osisko Metals may determine not to proceed with the transaction should there be a change in market conditions or investor interest or should another opportunity arise that would similarly enhance value for Osisko Metals’ shareholders.

Osisko Metals will provide updates when further details of the proposed transaction are determined.

Scientific and Technical Disclosure

Qualified Person

The scientific and technical information within this news release was reviewed and approved by Jared Hansen, P.Geo. (APEGNB M9393) a “qualified person” within the meaning of NI 43-101 – Standards of Disclosure for Mineral Projects who is not independent of the Company for purposes of Section 1.5 of NI 43-101.

Cautionary Note Regarding Historical Mineral Resource Estimate

The historical mineral resource estimate for the Mount Fronsac deposit disclosed herein is based on historical data and reports. A qualified person has not done sufficient work to classify the historical estimate as a current mineral resource. The Company is not treating the historical estimate as a current mineral resource as defined in NI 43-101. The historical estimate should not be relied upon. There is no guarantee that any part of the historical mineral resource estimate will be confirmed as a current mineral resource or upgraded to an indicated or measured mineral resource category with additional work. Readers are cautioned that the historical mineral resource estimate does not use categories consistent with CIM Definition Standards on Mineral Resources and Mineral Reserves. Significant capital expenditure and additional technical work, including drilling and analysis, would be required to verify and, if warranted, upgrade or reclassify the historical estimate as a current mineral resource.

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 Project is located near Murdochville in Québec’s Gaspé Peninsula. The Company is currently focused on resource expansion of the Gaspé Copper deposits, with current pit-constrained Measured and Indicated Mineral Resources of 1.83 Bt averaging 0.32% CuEq and Inferred Mineral Resources of 239 Mt averaging 0.46% CuEq (in compliance with NI 43-101). For more information, see the technical report titled “NI 43-101 Technical Report on the Gaspé Copper Project with an Updated Mineral Resource Estimate for the Copper Mountain Deposit, Québec, Canada” dated May 28, 2026 (with an effective date of January 17, 2026), a copy of which is available on SEDAR+ (www.sedarplus.ca) under Osisko Metals’ issuer profile. 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 averaging 5.52% ZnEq and Inferred Mineral Resources of 8.3 Mt averaging 5.64% ZnEq (in compliance with NI 43-101). For more information, see the technical report titled “NI 43-101 Technical Report, Pine Point Zinc-Lead Project, Mineral Resource Estimate Update, Hay River, Northwest Territories, Canada” dated August 9, 2024 (with an effective date of May 31, 2024), a copy of which is available on SEDAR+ (www.sedarplus.ca) under Osisko Metals’ issuer profile. 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.