Alamos Gold Extends Higher-Grade Mineralization within Multiple Hanging Wall Zones Near Existing Infrastructure at Young-Davidson

Press Release

TORONTO, Jan. 30, 2026 — Alamos Gold Inc. (TSX:AGI; NYSE:AGI) (“Alamos” or the “Company”) today reported new results from its underground exploration program at the Young-Davidson mine. Underground exploration drilling from both the mid and lower mine extended higher-grade gold mineralization within multiple zones in the hanging wall of the Young-Davidson deposit. In addition, expansion drilling within the Young-Davidson syenite continues to extend gold mineralization beyond Mineral Reserves and Mineral Resources.

South Syenite Zone: high-grade gold mineralization intersected within a syenite intrusion located in the hanging wall, 285 metres (“m”) south of the Northgate Shaft in an area that has seen limited historical drilling. (Figures 1 and 2). New highlights include¹:

• 16.36 g/t Au (6.65 g/t Au cut) over 17.90 m (YMEX24-9305-150)² including;
  • 116.50 g/t Au (25.00 g/t Au cut) over 1.00 m;
  • 80.80 g/t Au (25.00 g/t Au cut) over 1.00 m; and
  • 36.95 g/t Au (23.65 g/t Au cut) over 2.00 m.
• 9.15 g/t Au (5.56 g/t Au cut) over 22.00 m (YMEX24-9440-176) including;
  • 44.03 g/t Au (17.70 g/t Au cut) over 3.00 m.

• 10.67 g/t Au (6.90 g/t Au cut) over 16.50 m (YMEX24-9305-150)² including;
  • 63.90 g/t Au (25.00 g/t Au cut) over 1.60 m.
• 5.87 g/t Au (4.38 g/t Au cut) over 25.00 m (YMEX24-9440-170) including;
  • 21.19 g/t Au (11.89 g/t Au cut) over 4.00 m; and
• 4.89 g/t Au over 7.00 m (YMEX25-9440-206).

Mid-Mine Hanging Wall Zones: high grade gold mineralization extended within new hanging wall zone discovered in 2024. The zone contains a new style of mineralization and is located in proximity to existing infrastructure, to the south of existing Mineral Reserves and Resources. (Figures 1 and 3). New highlights include¹:

• 10.12 g/t Au (3.27 g/t Au cut) over 17.30 m (YMEX25-9620-247) including;
  • 143.50 g/t Au (25.00 g/t Au cut) over 1.00 m.
• 12.09 g/t Au (5.40 g/t Au cut) over 7.00 m (YMEX25-9620-245) including;
  • 71.80 g/t Au (25.00 g/t Au cut) over 1.00 m.
• 2.63 g/t Au over 26.85 m (YMEX24-9500-190);
• 2.71 g/t Au over 19.55 m (YMEX24-9500-188);
• 4.13 g/t Au over 12.65 m (YMEX24-9500-186)² including;
  • 17.41 g/t Au over 1.15 m.
• 5.17 g/t Au (4.56 g/t Au cut) over 7.90 m (YMEX25-9800-210) including;
  • 29.40 g/t Au (25.00 g/t Au cut) over 1.10 m.
• 38.10 g/t Au (25.00 g/t Au cut) over 1.00 m (YMEX25-9620-229);
• 9.46 g/t Au (8.71 g/t Au cut) over 4.00 m (YMEX24-9500-190);
• 10.10 g/t Au (9.35 g/t Au cut) over 3.55 m (YMEX25-9620-230) including;
  • 20.76 g/t Au (18.87 g/t Au cut) over 1.40 m; and
• 12.81 g/t Au (7.47 g/t Au cut) over 2.35 m (YMEX25-9800-216) including;
  • 50.10 g/t Au (25.00 g/t cut) over 0.50 m.

Young Davidson Syenite – expansion drilling continues to extend gold mineralization beyond Mineral Reserves and Mineral Resources. New highlights include¹:

• 4.50 g/t Au (4.03 g/t Au cut) over 15.65 m (YMEX25-9620-224) including;
  • 21.38 g/t Au (17.73 g/t Au cut) over 2.00 m.
• 7.45 g/t Au (4.35 g/t Au cut) over 8.50 m (YMEX25-9620-225) including;
  • 49.00 g/t Au (25.00 g/t Au cut) over 1.10 m.
• 4.12 g/t Au over 13.85 m (YMEX24-9305-192);
• 5.83 g/t Au over 8.00 m (YMEX25-9305-193);
• 5.54 g/t Au over 7.00 m (YMEX25-9800-208);
• 30.40 g/t Au (25.00 g/t Au) over 1.10 m (YMEX24-9710-185);
• 4.53 g/t Au over 6.00 m (YMEX25-9620-221); and
• 7.99 g/t Au over 3.00 m (YMEX25-9305-200).

¹Gold composites are generated using a 1.0 g/t Au cut-off and include no more than 7.0 m of consecutive internal waste. Drillhole composite intervals reported as “cut” include higher grade samples which have been cut to 25.00 g/t Au. All composite intervals are reported as downhole core length. Based on review of core angles, true width is generally estimated to be 50-80% of downhole core length. Additional drilling and interpretation is ongoing to further define the geometry and extent of the mineralized zones.

²Included in YE2024 Resource.

“Our dual focus over the past year at Young-Davidson was on continuing to extend gold mineralization within the main structure, while also targeting higher-grades within the hanging wall. The program was successful on both fronts, most notably within the hanging wall where we continue to intersect higher-grade mineralization across multiple zones. Given their proximity to existing infrastructure, and higher grades, these zones represent a significant upside opportunity,” said John A. McCluskey, President and Chief Executive Officer.

New highlight intercepts can be found in Table 1 and in Figures 1, 2, and 3 at the end of this news release.

2025 Exploration Drilling Program – Young Davidson

Exploration spending at Young-Davidson totaled $13.1 million in 2025, including 34,080 m of exploration drilling across 81 holes. Additionally, 448 m of underground exploration development was completed to establish an exploration drift and drill platforms to the south of the deposit to more effectively test higher grade mineralization defined in the hanging wall.

Underground exploration drilling remains focused on two primary areas. The first is continuing to extend mineralization within the Young-Davidson syenite, which hosts the majority of Mineral Reserves and Mineral Resources. The second is to test and expand on higher grade gold mineralization that has been intersected within two areas of focus in the hanging wall of the deposit. Of the 81 holes drilled in 2025, more than half were completed in the latter part of year and after the cut off date for year-end 2025 Mineral Reserve and Resource reporting.

Young-Davidson South Syenite Zone (“YD South Zone”)

Drilling from the 9305-level and 9440-level in 2025 has been successful in intersecting high-grade gold mineralization within a syenite intrusion in the hanging wall to the southeast of the main Young Davidson Deposit. This area is 285 m south of the Northgate Shaft and has seen limited historical drilling. Gold mineralization is associated with 3-20% pyrite and occurs both as wide, low- to moderate-grade mineralization, and within narrower, high-grade shear zones and quartz veins (Figures 1 and 2).

Drilling will continue in 2026 with the objective of further expanding upon the high-grade mineralization where it remains open to the east and up/down dip.

New highlights include^1,2:

• 16.36 g/t Au (6.65 g/t Au cut) over 17.90 m (YMEX24-9305-150)² including;
  • 116.50 g/t Au (25.00 g/t Au cut) over 1.00 m;
  • 80.80 g/t Au (25.00 g/t Au cut) over 1.00 m; and
  • 36.95 g/t Au (23.65 g/t Au cut) over 2.00 m.
• 9.15 g/t Au (5.56 g/t Au cut) over 22.00 m (YMEX24-9440-176) including;
  • 44.03 g/t Au (17.70 g/t Au cut) over 3.00 m.

• 10.67 g/t Au (6.90 g/t Au cut) over 16.50 m (YMEX24-9305-150)² including;
  • 63.90 g/t Au (25.00 g/t Au cut) over 1.60 m.
• 5.87 g/t Au (4.38 g/t Au cut) over 25.00 m (YMEX24-9440-170) including;
  • 21.19 g/t Au (11.89 g/t Au cut) over 4.00 m.
• 4.89 g/t Au over 7.00 m (YMEX25-9440-206);
• 4.48 g/t Au over 7.00 m (YMEX24-9440-168);
• 2.86 g/t Au over 10.00 m (YMEX24-9440-172);
• 2.77 g/t Au over 8.00 m (YMEX25-9305-193);
• 8.80 g/t Au over 2.00 m (YMEX24-9440-171);
• 2.52 g/t Au over 5.00 m (YMEX24-9440-171);
• 2.37 g/t Au over 10.00 m (YMEX24-9440-175);
• 20.10 g/t Au over 1.00 m (YMEX24-9440-176);
• 9.94 g/t Au over 1.90 m (YMEX24-9440-176);
• 12.85 g/t Au over 1.00 m (YMEX24-9440-169); and
• 4.92 g/t Au over 2.00 m (YMEX24-9440-171).

Young-Davidson Mid-Mine Hanging Wall Zones

Drilling from the 9620 and 9500 levels is focused on expanding on higher-grade gold mineralization in the hanging wall sediments, syenite, and mafic-ultramafic lithologies that was initially defined in 2024. These zones are located in proximity to existing infrastructure and south of existing Mineral Reserves and Resources.

The 2025 drill program was successful in continuing to define and expand a new style of higher-grade mineralization that is hosted in hanging wall stratigraphy including a folded sequence of conglomerates, volcanics, and syenite intrusions. Higher-grade gold mineralization is associated with 3-15% pyrite and occurs both as wide, low- to moderate-grade mineralization, and within narrower, high-grade structures (Figures 1 and 3).

In 2025, a 448 m hanging wall exploration drift was established through the hanging wall mineralization, and further to the south to provide additional optimized drill platforms to effectively test the controls, geometry, and continuity of the higher-grade mineralization identified in 2024. Drilling commenced from this hanging wall exploration drift in the third quarter of 2025. To date, 31 holes have been completed, of which 18 are being reported in this release, and assays are pending for 13 of the holes.

New highlights include¹:

• 10.12 g/t Au (3.27 g/t Au cut) over 17.30 m (YMEX25-9620-247) including;
  • 143.50 g/t Au (25.00 g/t Au cut) over 1.00 m.
• 12.09 g/t Au (5.40 g/t Au cut) over 7.00 m (YMEX25-9620-245) including;
  • 71.80 g/t Au (25.00 g/t Au cut) over 1.00 m.
• 2.63 g/t Au over 26.85 m (YMEX24-9500-190);
• 2.71 g/t Au over 19.55 m (YMEX24-9500-188);
• 4.13 g/t Au over 12.65 m (YMEX24-9500-186)² including;
  • 17.41 g/t Au over 1.15 m.
• 5.17 g/t Au (4.56 g/t Au cut) over 7.90 m (YMEX25-9800-210) including;
  • 29.40 g/t Au (25.00 g/t Au cut) over 1.10 m.
• 38.10 g/t Au (25.00 g/t Au cut) over 1.00 m (YMEX25-9620-229);
• 9.46 g/t Au (8.71 g/t Au cut) over 4.00 m (YMEX24-9500-190);
• 2.89 g/t Au over 13.00 m (YMEX25-9620-226);
• 2.39 g/t Au over 15.50 m (YMEX25-9620-222);
• 10.10 g/t Au (9.35 g/t Au cut) over 3.55 m (YMEX25-9620-230) including;
  • 20.76 g/t Au (18.87 g/t Au cut) over 1.40 m.
• 12.81 g/t Au (7.47 g/t Au cut) over 2.35 m (YMEX25-9800-216) including;
  • 50.10 g/t Au (25.00 g/t cut) over 0.50 m.
• 2.08 g/t Au over 14.10 m (YMEX25-9620-245);
• 2.45 g/t Au over 11.90 m (YMEX25-9620-246);
• 4.04 g/t Au over 7.00 m (YMEX24-9500-189);
• 13.75 g/t Au over 2.00 m (YMEX25-9620-231);
• 3.12 g/t Au over 8.60 m (YMEX25-9620-247);
• 3.05 g/t Au over 7.45 m (YMEX25-9500-202); and
• 3.88 g/t Au over 5.75 m (YMEX25-9620-230).

Young Davidson Syenite – expansion drilling from underground drill platforms across the deposit continues to target and successfully extend gold mineralization beyond existing Mineral Reserves and Mineral Resources within the main syenite unit. Young-Davidson has maintained at least a 13-year Mineral Reserve life since 2011. With the deposit open and depth and to the west, there is excellent potential for the track record to continue. New highlights from expansion drilling include¹:

• 4.50 g/t Au (4.03 g/t Au cut) over 15.65 m (YMEX25-9620-224) including;
  • 21.38 g/t Au (17.73 g/t Au cut) over 2.00 m.
• 7.45 g/t Au (4.35 g/t Au cut) over 8.50 m (YMEX25-9620-225) including;
  • 49.00 g/t Au (25.00 g/t Au cut) over 1.10 m.
• 4.12 g/t Au over 13.85 m (YMEX24-9305-192);
• 5.83 g/t Au over 8.00 m (YMEX25-9305-193);
• 5.54 g/t Au over 7.00 m (YMEX25-9800-208);
• 30.40 g/t Au (25.00 g/t Au cut) over 1.10 m (YMEX24-9710-185);
• 4.53 g/t Au over 6.00 m (YMEX25-9620-221);
• 7.99 g/t Au over 3.00 m (YMEX25-9305-200);
• 2.61 g/t Au over 9.00 m (YMEX24-9305-180) including;
  • 14.85 g/t Au over 1.00 m;
• 6.07 g/t Au over 3.10 m (YMEX25-9620-224);
• 3.37 g/t Au over 5.54 m (YMEX24-9500-187) including;
  • 12.50 g/t Au over 1.00 m.
• 3.50 g/t Au over 5.05 m (YMEX24-9500-189);
• 2.23 g/t Au over 7.80 m (YMEX25-9800-213);
• 16.75 g/t Au over 1.00 m (YMEX24-9710-185A);
• 2.07 g/t Au over 7.57 m (YMEX25-9500-195); and
• 3.41 g/t Au over 4.50 m (YMEX25-9305-193).

¹Gold composites are generated using a 1.0 g/t Au cut-off and include no more than 7.0 m of consecutive internal waste. Drillhole composite intervals reported as “cut” include higher grade samples which have been cut to 25.00 g/t Au. All composite intervals are reported as downhole core length. Based on review of core angles, true width is generally estimated to be 50-80% of downhole core length. Additional drilling and interpretation is ongoing to further define the geometry and extent of the mineralized zones.

²Included in YE2024 Resource.

Qualified Persons

Scott R.G. Parsons, P.Geo., FAusIMM, Alamos Gold’s Vice President, Exploration, has reviewed and approved the scientific and technical information contained in this news release. Scott R.G. Parsons is a “Qualified Person” as defined by Canadian Securities Administrators’ National Instrument 43-101 – Standards of Disclosure for Mineral Projects.

Exploration programs at the Young Davidson Mine are directed and supervised by Niels Hendrikx, P.Geo., Geological Superintendent at the Young Davidson Mine. Niels Hendrikx is a “Qualified Person” as defined by Canadian Securities Administrators’ National Instrument 43-101 – Standards of Disclosure for Mineral Projects.

Quality Assurance and Quality Control

Alamos Gold maintains an internal Quality Assurance / Quality Control (QA/QC) program at the Young Davidson Mine to ensure sampling and analysis of all exploration work is conducted in accordance with best practices.

Access to the Young Davidson Mine is controlled by security personnel. Drill core is logged and sampled at core logging facilities within the mine site under the supervision of a Qualified Geologist. A geologist marks the individual samples for analysis, and sample intervals, sample numbers, standards and blanks are entered into the database.

Mine exploration core (NQ-diameter) is cut in half using an electric core saw equipped with a diamond tipped blade. One half of the core is placed into a plastic sample bag and sealed with zip ties in preparation for shipment. The other half of the core is returned to the core box and retained for future reference. The samples are placed in large heavy-duty nylon reinforced Fabrene bags, which are identified and sealed before being placed on pallets. The core samples are picked up at the mine site and mine samples are delivered to ALS laboratories, located in Timmins, Ontario.

Gold is analyzed by a 30 gram fire assay with an Atomic Absorption (AA) finish. Mine exploration samples greater than 8.0 g/t Au are re-analyzed using gravimetric finish methods. ALS is a certified laboratory and has an internal quality control (“QC”) program that includes insertion of reagent blanks, reference materials, and pulp duplicates.

The Corporation inserts QC samples (blanks and reference materials) at regular intervals to monitor laboratory performance.

Underground definition drill core (BQ-diameter) is assayed using whole core samples at the Young-Davidson Mine on-site laboratory. The laboratory has been operating since 2012 and has undergone regular external audits, most recently by Qualitica Consulting Inc. in 2025. The Young-Davidson laboratory maintains a rigorous assay quality control program including reagent blanks, insertion of reference materials, and pulp duplicates. Blanks and reference materials are inserted with underground definition drill core samples on a routine basis. Gold is analyzed by a 30 gram fire assay with an Atomic Absorption (AA) finish. Samples with fire assay grades greater than 8.0 g/t Au are re-analyzed using gravimetric finish methods. In addition, sample pulps are routinely submitted for check assays to an accredited commercial laboratory.

The Young-Davidson Mine QA/QC procedures described in detail in the January 25, 2017 Technical Report filed on SEDAR+ (www.sedarplus.ca).

About Alamos

Alamos is a Canadian-based intermediate gold producer with diversified production from three operations in North America. This includes the Island Gold District and Young-Davidson mine in northern Ontario, Canada, and the Mulatos District in Sonora State, Mexico. Additionally, the Company has a strong portfolio of growth projects, including the Phase 3+ Expansion at Island Gold, and the Lynn Lake project in Manitoba, Canada. Alamos employs more than 2,400 people and is committed to the highest standards of sustainable development. The Company’s shares are traded on the TSX and NYSE under the symbol “AGI”.

FOR FURTHER INFORMATION, PLEASE CONTACT:

Scott K. Parsons
Senior Vice President, Corporate Development & Investor Relations
(416) 368-9932 x 5439
Khalid Elhaj
Vice President, Business Development & Investor Relations
(416) 368-9932 x 5427
ir@alamosgold.com

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