Mr. John McCluskey reports

ALAMOS GOLD ANNOUNCES ONGOING EXPLORATION SUCCESS AT MULATOS INCLUDING EXPANDING HIGH-GRADE MINERALIZATION AT PUERTO DEL AIRE AND INTERSECTING WIDE INTERVALS OF SIGNIFICANT GOLD MINERALIZATION AT CAPULIN TARGET

Alamos Gold Inc. has released new results from continuing surface exploration drilling within the Mulatos district. Drilling continues to extend high-grade gold mineralization outside of mineral reserves and resources at Puerto Del Aire (PDA). PDA is a higher-grade underground deposit adjacent to the Mulatos pit. Additionally, step-out drilling at the Capulin regional target continues to intersect wide intervals of significant gold mineralization. Capulin is located four kilometres (km) east of the Mulatos open pit. All amounts are in U.S. dollars, unless otherwise stated.

Puerto Del Aire (PDA)

Additional high-grade gold mineralization extended beyond mineral reserves and resources at PDA. This is expected to support further growth in the size of the deposit following a 71-per-cent increase in combined mineral reserves and resources in 2022 to total 1.0 million ounces. This growth will be incorporated into a development plan expected to be completed in the fourth quarter of 2023. An expanded drill program is continuing with the deposit open in multiple directions. All reported composite widths are estimated true width of the mineralized zones. New highlights include:

• 41.46 grams per tonne Au (18.87 g/t cut) over 7.05 metres (23MUL122);
• 18.32 g/t Au (15.13 g/t cut) over 9.50 m (23MUL120);
• 13.62 g/t Au (13.62 g/t cut) over 9.45 m (23MUL120);
• 85.80 g/t Au (40.00 g/t cut) over 1.20 m (23MUL165);
• 5.58 g/t Au (5.58 g/t cut) over 17.60 m (23MUL165);
• 10.42 g/t Au (10.42 g/t cut) over 6.00 m (23MUL139).

Capulin target

Step-out drilling continues to intersect wide, significant intervals of oxide and sulphide gold mineralization within a breccia adjacent to the Capulin fault. This includes the best hole drilled to date at Capulin (23REF022), a 25-metre (m) step-out from the previously reported initial hole drilled in this area 23REF012 (2.01 g/t Au over 82.45 m core length, including 4.81 g/t Au over 16.40 m and 5.38 g/t Au over 12.35 m). Drilling continues to test the geometry of the breccia unit and the extent of the gold mineralization, as well as targets across the broader Capulin area. New highlights include:

• 2.73 g/t Au over 120.85 m core length, including 9.31 g/t Au over 29.05 m (23REF022).

Note: Drill hole composite gold grades reported as cut at PDA may include higher-grade samples which have been cut to 40 g/t Au. Drill hole composite gold grades reported at Capulin as uncut.

"Step-out drilling at PDA continues to yield high-grade results which we expect will drive a further increase in mineral reserves and resources. Given our exploration success and with the deposit open in multiple directions, we have expanded the exploration budget for the second time this year to allow for an aggressive ongoing drill program. Drilling completed to date will be incorporated into a development plan for PDA which is expected to be finalized in the fourth quarter. We expect this will outline a significant mine life extension at Mulatos with another attractive, high-return project," said John A. McCluskey, president and chief executive officer.

"Our regional program also continues to highlight the long-term potential in the Mulatos district. Following up on our initial success at Capulin earlier this year, step-out drilling has confirmed the significant potential in the area, returning the best hole to date. Mulatos has a long history of mineral reserve replacement through the discovery of a number of high-return deposits within the district. With our ongoing exploration success at PDA, and regional targets like Capulin, we see excellent potential for that track record to continue," Mr. McCluskey added.

New highlight intercepts can be found in the attached tables.

2023 exploration budget -- Mulatos

Reflecting continuing exploration success, the 2023 exploration budget at Mulatos has been increased for a second time this year to $24.5-million. This is up from the initial 2023 budget of $17-million and more than triple the $7-million budget in 2022.

This includes 50,000 m of surface exploration drilling at PDA, up from the expanded 35,000 m program announced in May and initial budget of 16,000 m, reflecting continuing success in 2023.

Additionally, the regional exploration budget has doubled from 2022 to 34,000 m with the focus on several high-priority targets including Refugio, Halcon West, Carricito, Bajios and Cerro Pelon West.

Puerto Del Aire

PDA is a higher-grade underground deposit located adjacent to the main Mulatos pit, and comprises multiple mineralized zones including PDA, Gap, Victor and Estrella. Continuing exploration success has driven substantial growth in the deposit over the past two years. This included a 70-per-cent increase in mineral reserves to 728,000 ounces at the end of 2022 with grades increasing 4 per cent to 4.84 g/t Au. Mineral reserves and resources at PDA now total 1.0 million ounces across all categories, up 71 per cent from the end of 2021. Over the past two years, discovery costs at PDA have averaged $10 per ounce.

The initial focus of the surface exploration program in 2023 has been the main PDA zone where drilling continues to extend high-grade mineralization beyond mineral reserves and resources. Given continuing exploration success and with the deposit open in multiple directions, there is excellent potential for further growth in mineral reserves and resources. As of Sept. 1, 2023, 35,348 m of drilling has been completed in 114 holes at PDA.

Six surface drill rigs are currently in operation with the expanded 50,000 m program expected to be completed late in the fourth quarter of 2023. All drilling completed as of July 31, 2023, including new results in this press release, will be incorporated into a development plan for PDA. This is expected to be completed in the fourth quarter of 2023 and outline a significant mine life extension at Mulatos. Drilling completed through the rest of this year will be incorporated into subsequent updates.

PDA is expected to be mined from underground, and accessed from a ramp and development drifts off the main Mulatos pit. This will significantly reduce the development needed to access the deposit. The company is evaluating an expansion of the existing mill at Mulatos to process ore from PDA, or the construction of a new mill that would utilize the existing mill and crushing infrastructure. The existing mill was previously used to process underground ore from San Carlos.

Regional exploration update

As of Sept. 1, 2023, 22,356 m of regional surface exploration drilling has been completed at several targets in the Capulin, Halcon West, Cerro Pelon West and Carricito areas. The Capulin target continues to be a high-priority exploration target. Based on success to date, two additional rigs have been allocated to Capulin bringing the total to three drills focused in the area. Capulin is located approximately four kilometres east of the Mulatos open pit and two kilometres east of the former San Carlos open pit, in an area that had seen limited historical exploration.

As released on May 15, 2023, drill hole 23REF012 intersected a significant interval of oxide and sulphide gold mineralization, 2.01 g/t Au over 82.45 m core length including 4.81 g/t Au over 16.40 m and 5.38 g/t Au over 12.35 m in a breccia unit adjacent to the Capulin fault zone. This hole was a 75 m step-out to the northwest from drill hole 17REF015, which was drilled in 2017 and intersected 1.00 g/t Au over 13.80 m. The recognition of the mineralized breccia in 23REF012 and recent mapping have triggered a reinterpretation of the geology in this area east of the past-producing San Carlos mine.

Drill hole 23REF022 was completed as a 25 m step-out to the west of 23REF012, and intersected 2.73 g/t Au over 120.85 m core length, including 9.31 g/t Au over 29.05 m in a wider and higher-grade zone of oxide and sulphide gold mineralization in the breccia. In addition, drill hole 23REF021 was completed as another 25 m step-out to the east and interested 3.65 g/t Au over 6.00 m in the breccia. Hole 23REF020 was drilled approximately 500 m to the east and intersected 0.99 g/t Au over 8.80 m in the breccia unit.

Two drills are currently focused on 25 m and 50 m step-out drilling around holes 23REF012 and 23REF022 to test the geometry and extent of the gold mineralization, and the breccia unit. The third drill continues to test targets in the broader Capulin target area, where gold mineralization identified in grab samples was collected over a two-kilometre strike length along the Capulin fault zone.

Qualified persons

Scott R.G. Parsons, PGeo, FAusIMM, Alamos Gold's vice-president, exploration, has reviewed and approved the scientific and technical information contained in this news release. Mr. Parsons is a qualified person as defined by Canadian Securities Administrators' National Instrument 43-101 -- Standards of Disclosure for Mineral Projects.

Exploration programs at Mulatos are directed and supervised by Michele Cote, PGeo, Alamos Gold's chief exploration geologist, corporate. Mr. Cote 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 Mulatos to ensure sampling and analysis of all exploration work is conducted in accordance with best practices.

Access to the Mulatos property is controlled by security personnel. The drill core is logged and sampled at the core logging facility within the mine site under the supervision of a qualified geologist. A geologist marks the individual samples for analysis, and sample intervals, based on lithology and alteration, standards and blanks are entered into the database. The core is cut in half using an electric core saw equipped with a diamond tipped blade. One-half of the core is placed into a micropore sample bag and sealed with a cable tie in preparation for shipment. The other one-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 micropore bags, which are identified and sealed before being dispatched. The core samples are picked up at the mine site and delivered to Bureau Veritas Commodities Canada Ltd. laboratory in Hermosillo, Mexico.

Gold is analyzed by 30-gram lead collection fire assay fusion (FA) that ends with an atomic absorption spectroscopy finish (AAS). Samples greater than 5.0 g/t Au are reanalyzed starting again with an FA process but ending with a gravimetric finish (GRAV). Bureau Veritas is an ISO/IEC 17025-accredited laboratory, and has internal quality control (QC) programs that include insertion of reagent blanks, reference materials and pulp duplicates that are in line with normal requirements, as well as participating in yearly proficiency tests to evaluate lab performance.

The corporation inserts QC samples (blanks and reference materials) at regular intervals to monitor laboratory performance. Cross-check assays are completed on a regular basis in a secondary accredited laboratory.

About Alamos Gold Inc.

Alamos is a Canadian-based intermediate gold producer with diversified production from three operating mines in North America. This includes the Young-Davidson and Island Gold mines in Northern Ontario, Canada, and the Mulatos mine in Sonora state, Mexico. Additionally, the company has a strong portfolio of growth projects, including the phase 3 plus expansion at Island Gold and the Lynn Lake project in Manitoba, Canada. Alamos employs more than 1,900 people and is committed to the highest standards of sustainable development. The company's shares are traded on the Toronto and New York stock exchanges under the symbol AGI.

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