All amounts are in United States dollars, unless otherwise stated.

Toronto, Ontario (October 29, 2025) - Alamos Gold Inc. (TSX:AGI; NYSE:AGI) (“Alamos” or the “Company”) today reported its financial results for the quarter ended September 30, 2025.

“We delivered a number of new financial records in the third quarter including record free cash flow of $130 million, while continuing to fund our high-return growth projects. This was driven by a further increase in production to 141,700 ounces and significant margin expansion,” said John A. McCluskey, President and Chief Executive Officer.

“Given unplanned downtime of the Magino mill at the end of September, and lower expected underground grades from Island Gold due to a seismic event in October, we are revising our 2025 production guidance lower by approximately 6%. These challenges are short-term and are not reflective of our strong outlook, nor our long-term track record. We expect a significant improvement starting in the fourth quarter with an 18% increase in production, and a 5% decrease in costs,” Mr. McCluskey added.

•Produced 141,700 ounces of gold, a 3% increase from the second quarter of 2025 reflecting stronger performances from both Mulatos and the Island Gold District. Third quarter production was slightly below the low end of quarterly guidance of 145,000 ounces, reflecting one week of unplanned downtime within the Magino mill due to a capacitor failure within the electrical house, which occurred during the last week of September

•Subsequent to quarter end, a seismic event occurred underground at Island Gold on October 17th. Mining activities continue at budgeted rates; however, this has delayed access to higher grade stopes in one mining front. As a result, grades mined are expected to be lower in the fourth quarter than budgeted. Combined with the unplanned downtime at the end of September at the Magino mill, the Company is updating its 2025 production guidance to a range of 560,000 to 580,000 ounces, a 6% decrease from original guidance (based on the mid-point)

•Fourth quarter production is expected to increase 18% (based on the mid-point) to between 157,000 and 177,000 ounces, the strongest quarter of the year, reflecting a substantial improvement across all three operations

•Generated record free cash flow1 of $130.3 million, while continuing to reinvest in high-return growth projects including the Phase 3+ Expansion, Lynn Lake, and PDA. This was a 54% increase from the second quarter of 2025, reflecting strong contributions from all three operations. At current gold prices, the Company expects strong ongoing free cash flow generation through the remainder of 2025, with significant growth starting in 2026 reflecting higher production and lower costs

•Sold 136,473 ounces of gold at an average realized price of $3,359 per ounce, generating record quarterly revenues of $462.3 million. The average realized gold price was below the London PM Fix price, reflecting the delivery of 12,346 ounces into the gold prepayment facility executed in July 2024 based on the prepaid price of $2,524 per ounce. The Company delivered 75% of the committed ounces under the facility during the first nine months of 2025

•Cash flow from operating activities increased to a record $265.3 million (including $275.3 million before changes in working capital and taxes paid1, or $0.65 per share), a 33% increase from the second quarter of 2025 reflecting strong margin expansion through higher gold prices and lower costs

•Total cash costs1 of $973 per ounce were 9% lower than the second quarter of 2025 and in-line with quarterly guidance. All-in sustaining costs ("AISC")1 of $1,375 per ounce decreased 7% from the second quarter of 2025, driven by the stronger operational performance at the Mulatos District. The Company is reporting total cash costs and AISC excluding the impact of mark-to-market adjustments for the revaluation of previously issued share-based compensation. This provides a better representation of the total costs associated with producing an ounce of gold and eliminates volatility associated with mark-to-market adjustments. Prior year periods have been updated to reflect these changes retrospectively. Mark-to-market adjustments to share-based instruments impact both total cash costs and AISC given the Company allocates these costs to mining and processing costs and share-based compensation expense in the condensed interim consolidated financial statements

•Total cash costs and AISC are expected to decrease 5% in the fourth quarter reflecting higher production and stronger performances from all three operations. The Company remains on track to achieve annual total cash cost and AISC guidance, which was revised in July

•Cost of sales of $194.1 million, or $1,422 per ounce, decreased 4% from the second quarter of 2025 on a per-ounce basis

•Reported net earnings for the quarter were $276.3 million, or $0.66 per share

•Adjusted net earnings1 were $155.5 million, or $0.37 per share. Adjusted net earnings includes net-of-tax adjustments for a reversal of impairment of $192.9 million, and unrealized losses on commodity hedge derivatives of $53.8 million, as well as adjustments for unrealized foreign exchange loss recorded within deferred taxes and foreign exchange loss totaling $15.4 million, and other adjustments of $2.9 million

•Cash and cash equivalents increased 34% from the second quarter of 2025 to $463.1 million at September 30, 2025 reflecting the record free cash flow generation. The Company remains well-positioned to internally fund all of its growth initiatives with strong ongoing free cash flow, net cash of $213.1 million, and $963.1 million of total liquidity

•Announced the sale of the Company's Turkish development projects, which consist of Kirazlı, Ağı Dağı and Çamyurt, to Tümad Madencilik Sanayi ve Ticaret A.Ş (“Tümad”) for total cash consideration of $470 million. The transaction closed in October upon which Alamos received the first payment of $160 million. The remaining cash payments, totaling $310 million are expected to be received on the first and second anniversaries of the closing of the transaction

•Closed the sale of the option to earn 100% interest in the non-core Quartz Mountain Gold Project (“Quartz Mountain”), located in Oregon, to Q-Gold Resources Ltd. (TSXV:QGR) (“Q-Gold”) in October. Quartz Mountain was sold for total consideration of up to $21 million and a 9.9% equity interest in Q-Gold

•With a growing cash balance of more than $600 million following the close of the sale of the Turkish projects and Quartz Mountain, the Company expects to reduce existing debt obligations, and will assess opportunities to be active on its share buyback

•The total recordable injury frequency rate2 ("TRIFR") was 0.97 in the third quarter, compared to 2.01 in the prior year period. For the first nine months of the year, TRIFR was 0.99, compared to 1.86 in the prior year period

•Alamos was recognized for the second consecutive year as a TSX30TM 2025 winner by the Toronto Stock Exchange. The annual ranking recognizes the 30 top performing stocks over a three-year period. Alamos’ share price increased 310% over the trailing three-year period

•Advanced the Phase 3+ Expansion of the Island Gold District. This included the shaft sink progressing to a depth of 1,350 metres ("m") in the third quarter, or 98% of the planned depth. The Phase 3+ Expansion remains on track for completion in the second half of 2026

•Published Alamos’ 2024 Environmental, Social and Governance (“ESG”) Report, outlining the Company’s progress on its ESG performance

(1) Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this press release and associated MD&A for a description and calculation of these measures.

(2) Frequency rate is calculated as incidents per 200,000 hours worked.

(1)Cost of sales includes mining and processing costs, royalties, and amortization expense.

(2)Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this press release and associated MD&A for a description and calculation of these measures.

(3)Sustaining finance leases at Island Gold District are not included as additions to mineral property, plant and equipment in cash flows used in investing activities.

(4)Cash and cash equivalents in the comparatives reflect the balance as at December 31, 2024.

(5)Average realized gold price for the three and nine months ended September 30, 2025 included the delivery of ounces into the gold prepayment facility based on the prepaid price of $2,524 per ounce.

(6)Comparative figures reflect the inclusion of the Magino Mine as of its acquisition on July 12, 2024.

(1)Cost of sales includes mining and processing costs, royalties, and amortization expense.

(2)Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this press release and associated MD&A for a description and calculation of these measures.

(3)For the purposes of calculating mine-site all-in sustaining costs, the Company does not include an allocation of corporate and administrative expense and corporate share-based compensation expense.

(4)Includes capitalized exploration at Island Gold District of $9.6 million and $20.3 million for the three and nine months ended September 30, 2025 ($3.8 million and $10.7 million for the three and nine months ended September 30, 2024 ).

(5)Includes capitalized exploration at Young-Davidson of $4.2 million and $9.1 million for the three and nine months ended September 30, 2025 ($1.5 million and $3.9 million for the three and nine months ended September 30, 2024).

(6)Includes capitalized exploration at Mulatos District of $7.6 million and $10.1 million for the three and nine months ended September 30, 2025 ($0.9 million and $5.9 million for the three and nine months ended September 30, 2024).

(7)The Island Gold District includes Island Gold and Magino mines for the three and nine months ended September 30, 2025. Comparative figures reflect the inclusion of the Magino Mine as of its acquisition on July 12, 2024.

(8)The Mulatos District includes Mulatos and La Yaqui Grande mines.

(9)Sustaining capital expenditures for Island Gold District include certain finance leases classified as sustaining.

•TRIFR1 of 0.97 in the third quarter

•Lost time injury frequency rate1 ("LTIFR") of 0.08 in the third quarter

•Alamos had 12 recordable injuries across its sites and one lost time injury in the third quarter

•Year-to-date TRIFR of 0.99 and LTIFR of 0.08

•Five reportable spills occurred in the third quarter

•One reportable effluent exceedance

•Continued reclamation activities at Mulatos for the Cerro Pelon, El Victor and San Carlos pits

•Cash donations to the Haileybury and New Liskeard food banks

•Committed CAD$43,000 to the Blanche River Health Foundation to support the installation of emergency room waiting clocks at Englehart and Kirkland Lake BRH sites, providing accurate and timely information to patients

•Provided new fitness equipment for the Elk Lake Recreation Centre to promote community wellbeing

•Sponsorship of multiple events and teams, including the Canadian Mining Games

•Supported student development through the Young Mining Professionals Scholarships initiative

•Ongoing support within the Mulatos District, including medical services, road maintenance, water distribution, and student scholarships

•The Mulatos District was awarded the prestigious Silver Helmet trophy for excellence in health and safety, for the third time since 2022, recognizing its outstanding management systems and performance

•Released the 2024 ESG Report, highlighting progress on ESG performance across the Company's operations, projects and offices

•Completed annual submissions to the Carbon Disclosure Project and S&P Global’s Corporate Sustainability Assessment, outlining ESG and climate performance

(1) Frequency rate is calculated as incidents per 200,000 hours worked.        

(1)Refer to the "Non-GAAP Measures and Additional GAAP" section of this press release and associated MD&A for a description of these measures.

(2)Total consolidated all-in sustaining costs include corporate and administrative, and share-based compensation expenses. Individual mine-site all-in sustaining costs do not include an allocation of corporate and administrative expense, and corporate share-based compensation expenses.

(3)Cost of sales includes mining and processing costs, royalties, amortization expense, and silver by-product credits, and is calculated based on the mid-point of total cash costs guidance.

(4)Initial annual guidance was issued on January 13, 2025. Cost guidance was revised on July 30, 2025, and production and capital guidance was revised on October 29, 2025.

Longer term, there is excellent potential to increase consolidated production to approximately one million ounces per year through a further expansion of the Island Gold District. The Expansion Study for the Island Gold District is scheduled to be released in the first quarter of 2026 and is expected to demonstrate the significant upside potential to the Base Case LOM Plan. The timeline of completion has shifted from the fourth quarter of 2025 to ensure all assays are included from recent delineation drilling to support further Mineral Reserve growth. The Expansion Study is expected to include a larger Mineral Reserve, through ongoing Mineral Resource conversion, and will evaluate a potential expansion of the mill to between 18,000 and 20,000 tpd, supporting higher underground mining rates from Island Gold, and open pit mining and processing rates from Magino.

(1)Cost of sales includes mining and processing costs, royalties, and amortization.

(2)Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this press release and associated MD&A for a description and calculation of these measures.

(3)For the purposes of calculating mine-site all-in sustaining costs, the Company does not include an allocation of corporate and administrative expense and corporate share-based compensation expense.

(4)Grams per tonne of gold.

(5)Mine-site free cash flow does not include lease payments which are classified as cash flows used in financing activities on the condensed interim consolidated financial statements.

(6)Comparative figures reflect the inclusion of the Magino Mine as of its acquisition on July 12, 2024.

(7)Includes ore stockpiled during the periods.

(8)Total waste mined includes operating waste and capitalized stripping.

(9)The Island Gold mill operated for 22 days during the quarter. It was on care and maintenance from July 16 to September 23, 2025, during which time all Island Gold ore was processed at the Magino mill. Island Gold mill average tpd reflects only active operating days.

(10)Magino mill results include Island Gold ore processed at Magino mill from July 16 through September 23, 2025.

Revenues of $213.0 million in the third quarter were 61% higher than the prior year period, driven by higher realized gold prices and an increase in ounces sold reflecting higher tonnes processed from the Island Gold District.

Similarly, revenues of $575.8 million during the first nine months of the year were 94% higher than the prior year period, primarily due to higher realized gold prices and increased ounces sold given the acquisition of Magino in July 2024.

Total capital expenditures were $83.4 million in the third quarter, including $45.6 million of growth capital and $5.1 million of capitalized exploration. Capital spending is expected to increase in the fourth quarter to be consistent with guidance. Growth capital spending remained primarily focused on the Phase 3+ Expansion, including shaft site infrastructure, paste plant, and shaft sinking. The shaft sink advanced to a depth of 1,350 m at the end of the third quarter, 98% of its ultimate planned depth. The shaft sink is scheduled to be completed early 2026, with initial production from the shaft infrastructure expected in the second half of 2026. The expansion of the Magino mill to 12,400 tpd is expected to be completed in the second half of 2026, to coincide with the completion of the Phase 3+ Expansion at Island Gold.

(1)Cost of sales includes mining and processing costs, royalties and amortization.

(2)Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this press release and associated MD&A for a description and calculation of these measures.

(3)For the purposes of calculating mine-site all-in sustaining costs, the Company does not include an allocation of corporate and administrative expense and corporate share-based compensation expense.

(4)Grams per tonne of gold.

Processed grades averaged 1.79 g/t Au in the third quarter, 14% lower than the prior year period due to lower underground grades mined and the addition of the low-grade stockpiles. Grades mined are expected to increase towards the upper end of full year guidance of 2.25 g/t Au in the fourth quarter. Combined with higher mining and processing rates, this is expected to drive a significant increase in production in the fourth quarter. Mill recoveries averaged 91% for the third quarter, in line with annual guidance.

Third quarter total cash costs of $1,200 per ounce and mine-site AISC of $1,476 per ounce were higher than the prior year period, primarily due to lower grades processed, higher royalty expense, and ongoing labour inflation. Total cash costs of $1,248 per ounce and mine-site AISC of $1,555 per ounce for the first nine months of year were higher than the comparative period, driven by the same factors.

(1)Cost of sales includes mining and processing costs, royalties, and amortization expense.

(2)Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this press release and associated MD&A for a description and calculation of these measures.

(3)For the purposes of calculating mine-site all-in sustaining costs, the Company does not include an allocation of corporate and administrative expense and corporate share-based compensation expense.

(4)Grams per tonne of gold.

Stacking rates averaged 11,000 tpd in the third quarter with grades and stacking rates both an improvement over the prior year period. This drove an increase in contained ounces stacked to 48,037 ounces. Recovery rates of 61% in the third quarter were below the annual guidance range, reflecting timing of recovery of ounces stacked on the leach pad.

Given the increased leach pad height, the recovery of a significant portion of ounces stacked over the past two quarters will be realized in the fourth quarter and into 2026.

•Shaft sinking advanced to a depth of 1,350 m, or 98% of the planned depth

•Commenced work on 1350 level shaft station

•Progressed mechanical and electrical outfitting for the water handling facility and shaft bin house

•Magino mill expansion to 12,400 tpd progressing well with earthworks completed and concrete foundation work ongoing. The footprint has been sized to accommodate a further potential expansion up to 20,000 tpd

•Detailed engineering for the larger Magino mill expansion up to 20,000 tpd is ongoing

•Advanced paste plant construction, with expected completion in first quarter of 2026

•Progressed new administrative complex construction with concrete foundation work ongoing

•Lateral development continued to support higher mining rates with the Phase 3+ Expansion

•Work advanced on the 115kV power line project in partnership with the Batchewana First Nation, including tree clearing, installing three bridges, and substation civil construction

1.Reflects updated initial capital estimates released in June 2025 as part of the Base Case LOM Plan, based on USD/CAD exchange $0.73:1 in 2025 and $0.74:1 in 2026 and 2027. Spent to date based on average USD/CAD of $0.73:1 since the start of 2022. Committed to date based on the spot USD/CAD rate as at September 30, 2025 of $0.72:1.

2.Amount spent to date accounted for on an accrual basis, including working capital movements.

Total initial growth capital for Lynn Lake was estimated to be $632 million in the 2023 Feasibility Study ("2023 Study"), based on input costs as of the fourth quarter of 2022. With the Manitoba wildfires adding an additional year to the project schedule, the Company is evaluating the impact of the delay on initial capital in addition to three years of inflation since the capital estimates were completed, which has averaged 5% annually.

The Company will provide an updated estimate during the first quarter of 2026 with the release of its three-year guidance.

On September 14, 2025, the Company announced that the Netherlands Subsidiaries have entered into a definitive agreement to sell their wholly owned Turkish subsidiary, which owns the Kirazlı, Ağı Dağı and Çamyurt projects, to Tümad, a mining company operating in the Republic of Türkiye, for total cash consideration of $470 million. The transaction closed on October 27, 2025 upon which Alamos received the first payment of $160 million. The remaining cash payments, totalling $310 million, are expected to be received on the first and second anniversaries of the closing of the transaction and are secured by bank guarantees issued by international banks with investment grade rating.

During the third quarter, 12,246 m of underground exploration drilling was completed in 49 holes, and 1,821 m of surface directional exploration drilling was completed in two holes at Island Gold. Additionally, 14,412 m of underground delineation drilling was completed in 50 holes, focused on infill drilling to convert Mineral Resources to Mineral Reserves. The surface delineation program, which initially commenced during the second quarter, continued to target Mineral Resource-to-Reserve conversion in the lower portion of Island East with 6,614 m completed across 10 holes. Furthermore, a total of 107 m of underground exploration drift development was completed during the third quarter.

Ongoing exploration success at PDA in 2024 drove a 9% increase in Mineral Reserves to 1.1 million ounces, with grades largely unchanged at 5.45 g/t Au. PDA is a higher-grade underground deposit located adjacent to the main Mulatos pit. The results of a positive internal economic study were announced in September 2024 and highlighted an attractive, low-cost, high-return project. With the amendment to the environmental permit received earlier this year, construction activities are expected to begin ramping up in the fourth quarter with first production anticipated mid-2027.

Cost of sales (which includes mining and processing costs, royalties, and amortization expense) were $194.1 million in the third quarter, 5% lower than the prior year period, primarily due to lower ounces sold. On a per ounce basis, cost of sales of $1,422 per ounce for the third quarter, were consistent with the prior year period. Key drivers of changes to cost of sales as compared to the prior year period were as follows:

This press release should be read in conjunction with the Company’s consolidated financial statements for the three-month period ended September 30, 2025 and associated Management’s Discussion and Analysis (“MD&A”), which are available from the Company's website, www.alamosgold.com, in the "Investors" section under "Reports and Financials", and on SEDAR+ (www.sedarplus.ca) and EDGAR (www.sec.gov).

The Company's senior management will host a conference call on Thursday, October 30, 2025 at 10:00 am ET to discuss the third quarter 2025 results. Participants may join the conference call via webcast or through the following dial-in numbers:

Toronto and International:                (416) 406-0743

Toll free (Canada and the United States):         (800) 898-3989

Participant passcode:                    4265146#

Webcast:                         www.alamosgold.com

A playback will be available until November 30, 2025 by dialling (905) 694-9451 or (800) 408-3053 within Canada and the United States. The pass code is 3824375#. The webcast will be archived at www.alamosgold.com.

Chris Bostwick, FAusIMM, Alamos’ Senior Vice President, Technical Services, who is a qualified person within the meaning of National Instrument 43-101 ("Qualified Person"), has reviewed and approved the scientific and technical information contained in this press release.

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”.

ir@alamosgold.com 

This press release contains or incorporates by reference “forward-looking statements” and “forward-looking information” as defined under applicable Canadian and U.S. securities legislation. All statements, other than statements of historical fact, which address events, results, outcomes or developments that the Company expects to occur are, or may be deemed, to be, forward-looking statements and are based on expectations, estimates and projections as at the date of this press release. Forward-looking statements are generally, but not always, identified by the use of forward-looking terminology such as "expect", “assume”, "believe", "anticipate", "intend", "objective", "estimate", “potential”, "prospective", "forecast", “target”, "goal", "aim", “on track”, "on pace", “outlook”, “continue”, “ongoing”, “plan” or variations of such words and phrases and similar expressions or statements that certain actions, events or results “may”, “could”, “would”, “might” or “will” be taken, occur or be achieved or the negative connotation of such terms.

Such statements in this press release include, but may not be limited to, guidance and expectations pertaining to: gold production; production potential; mining, processing, milling, stacking, and production rates; gold grades; gold prices; foreign exchange rates; free cash flow, mine-site free cash flow, total cash costs, all-in sustaining costs, mine-site all-in sustaining costs, capital expenditures, total sustaining and growth capital, capitalized exploration, budgets, tax rates and the payment of taxes, IRR, NPV; total liquidity; returns to stakeholders; impacts of inflation; mine plans; mine life; Mineral Reserve life; Mineral Reserves and Resources; exploration potential, budgets, focuses, programs, targets, and projected results; funding of growth initiatives; operational impacts on the natural environment; the Company's approach to reduction of its environmental footprint, greenhouse gas emissions, and related investments in new initiatives; the Company's climate change strategy and goals; community relations, engagement activities, and initiatives; corporate governance; synergies resulting from the integration of the Magino and Island Gold operations; processing of ore from Island Gold through the Magino mill; Magino mill expansion; paste plant construction project; increases to production, value of operation, and decreases to costs resulting from the intended completion of the Phase 3+ Expansion at Island Gold; intended infrastructure investments in, method of funding for, and timing of the completion of, the Phase 3+ Expansion; Island Gold District Expansion Study; construction of the 115kV powerline project, its estimated time of completion and its expected effect on GHG emissions; construction activities, capital spending and timing of initial production with respect to the Lynn Lake project and the PDA project; initial underground Mineral Resource at Cerro Pelon; the BT and Linkwood deposits near the Lynn Lake project; growing production, expanding margins, and increases in profitability; the quantum of consideration payable for the sale of Quartz Mountain to Q-Gold, including future guaranteed and milestone payments; the expected timing of remaining payments with respect to the sale of the Company's Turkish development projects; as well as other general information as to strategy, plans or future financial or operating performance, such as the Company’s expansion plans, project timelines, production plans and expected sustainable productivity increases, expected increases in mining activities and corresponding cost efficiencies, cost estimates, sufficiency of working capital for future commitments and other statements that express management’s expectations or estimates of future plans and performance.

Risk factors that may affect Alamos’ ability to achieve the expectations set forth in the forward-looking statements in this document include, but are not limited to: changes to current estimates of mineral reserves and resources; changes to production estimates (which assume accuracy of projected ore grade, mining rates, recovery timing and recovery rate estimates which may be impacted by unscheduled maintenance, weather issues, labour and contractor availability and other operating or technical difficulties); operations may be exposed to illnesses, diseases, epidemics and pandemics, the impact of any illness, disease, epidemic or pandemic on the broader market and the trading price of the Company's shares; provincial and federal orders or mandates (including with respect to mining operations generally or auxiliary businesses or services required for the Company’s operations) in Canada, Mexico and the United States; the duration of any regulatory responses to any illness, disease, epidemic or pandemic; government and the Company’s attempts to reduce the spread of any illness, disease, epidemic or pandemic which may affect many aspects of the Company's operations including the ability to transport personnel to and from site, contractor and supply availability and the ability to sell or deliver gold doré bars; fluctuations in the price of gold or certain other commodities such as, diesel fuel, natural gas, and electricity; changes in foreign exchange rates (particularly CAD, MXN and USD); the impact of inflation and any tariffs, trade barriers and/or regulatory costs; changes in the Company's credit rating; any decision to declare a quarterly dividend; employee and community relations; litigation and administrative proceedings and any resulting court or arbitral decision(s); disruptions affecting operations; availability of and increased costs associated with mining inputs and labour; delays with the Phase 3+ Expansion project at the Island Gold mine, construction of the 115kV powerline, expansion of the Magino mill, paste plant construction project, construction of the Lynn Lake Project, construction of the PDA project, and/or the development or updating of mine plans; changes with respect to the intended method of accessing, mining the deposit, and processing any ore at PDA; risks associated with the start-up of new mines; the risk that the Company’s mines may not perform as planned; with respect to the sale of Quartz Mountain, the failure by Q-Gold to make the requisite future payments and actions required to trigger milestone payments not being implemented or coming to fruition; with respect to the sale of the Company's Turkish development projects, default on either or both of the Anniversary Payments; uncertainty with the Company’s ability to secure additional capital to execute its business plans; the speculative nature of mineral exploration and development, including the risks of obtaining and maintaining necessary licenses and permits, including the necessary licenses, permits, authorizations and/or approvals from the appropriate regulatory authorities for the Company’s development stage and operating assets; labour and contractor availability (and being able to secure the same on favourable terms); contests over title to properties; expropriation or nationalization of property; inherent risks and hazards associated with mining and mineral processing including environmental hazards, industrial hazards, industrial accidents, unusual or unexpected formations, pressures and cave-ins; changes in national and local government legislation, controls or regulations in Canada, Mexico, the United States and other jurisdictions in which the Company does or may carry on business in the future; increased costs and risks related to the potential impact of climate change; failure to comply with environmental and health and safety laws and regulations; disruptions in the maintenance or provision of required infrastructure and information technology systems; risk of loss due to sabotage, protests and other civil disturbances; the impact of global liquidity and credit availability and the values of assets and liabilities based on projected future cash flows; risks arising from holding derivative instruments; and business opportunities that may be pursued by the Company.

Additional risk factors and details with respect to risk factors that may affect the Company’s ability to achieve the expectations set forth in the forward-looking statements contained in this press release are set out in the Company's latest 40-F/Annual Information Form under the heading “Risk Factors”, which is available on the SEDAR+ website at www.sedarplus.ca or on EDGAR at www.sec.gov. The foregoing should be reviewed in conjunction with the information, risk factors and assumptions found in this press release.

Measured, Indicated and Inferred Resources: All resource and reserve estimates included in this press release or documents referenced in this press release have been prepared in accordance with Canadian National Instrument 43-101 - Standards of Disclosure for Mineral Projects ("NI 43-101") and the Canadian Institute of Mining, Metallurgy and Petroleum (the "CIM") - CIM Definition Standards on Mineral Resources and Mineral Reserves, adopted by the CIM Council, as amended (the "CIM Standards"). NI 43-101 is a rule developed by the Canadian Securities Administrators, which established standards for all public disclosure an issuer makes of scientific and technical information concerning mineral projects. Mining disclosure in the United States was previously required to comply with SEC Industry Guide 7 (“SEC Industry Guide 7”) under the United States Securities Exchange Act of 1934, as amended. The U.S. Securities and Exchange Commission (the “SEC”) has adopted final rules, to replace SEC Industry Guide 7 with new mining disclosure rules under sub-part 1300 of Regulation S-K of the U.S. Securities Act (“Regulation S-K 1300”) which became mandatory for U.S. reporting companies beginning with the first fiscal year commencing on or after January 1, 2021. Under Regulation S-K 1300, the SEC now recognizes estimates of “Measured Mineral Resources”, “Indicated Mineral Resources” and “Inferred Mineral Resources”. In addition, the SEC has amended its definitions of “Proven Mineral Reserves” and “Probable Mineral Reserves” to be substantially similar to international standards.

International Financial Reporting Standards: The condensed interim consolidated financial statements of the Company have been prepared by management in accordance with International Financial Reporting Standard 34, Interim Financial Reporting, as issued by the International Accounting Standards Board. These accounting principles differ in certain material respects from accounting principles generally accepted in the United States of America. The Company’s reporting currency is the United States dollar unless otherwise noted.

•adjusted net earnings and adjusted earnings per share;

•cash flow from operating activities before changes in working capital and taxes paid;

•Company-wide free cash flow;

•total mine-site free cash flow;

•mine-site free cash flow;

•total cash costs per ounce of gold sold;

•AISC per ounce of gold sold;

•Mine-site AISC per ounce of gold sold;

•sustaining and non-sustaining capital expenditures; and

•adjusted earnings before interest, taxes, depreciation, and amortization ("Adjusted EBITDA")

The Company believes that these measures, together with measures determined in accordance with IFRS, provide investors with an improved ability to evaluate the underlying performance of the Company. Non-GAAP financial measures do not have any standardized meaning prescribed under IFRS, and therefore they may not be comparable to similar measures employed by other companies. The data is intended to provide additional information and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with IFRS. Management's determination of the components of non-GAAP and additional measures are evaluated on a periodic basis influenced by new items and transactions, a review of investor uses and new regulations as applicable. Any changes to the measures are duly noted and retrospectively applied as applicable.

•Foreign exchange gains or losses

•Items included in other loss

•Impairment expense/reversal of impairment

•Unrealized gain or loss on commodity derivatives

•Certain non-recurring items

•Foreign exchange gain or loss recorded in deferred tax expense

•The income and mining tax impact of items included in other loss

(1)Relates to overdue payables at the Magino mine and transaction costs incurred by Argonaut and paid by Alamos.

(1)Cash from operating activities for the Canadian operations excludes the impact of the 12,346 ounces and 37,038 ounces delivered into the gold prepayment arrangement for the three and nine months ended September 30, 2025. The non-cash adjustment to reflect the settlement of the gold prepayment arrangement is included in Company-wide free cash flow.

(2)Comparative figures reflect the inclusion of the Magino Mine as of its acquisition on July 12, 2024.

Total cash costs per ounce is a non-GAAP term typically used by gold mining companies to assess the level of gross margin available to the Company by subtracting these costs from the unit price realized during the period. This non-GAAP term is also used to assess the ability of a mining company to generate cash flow from operating activities. Total cash costs per ounce includes mining and processing costs plus applicable royalties, and net of by-product revenue and net realizable value adjustments. Total cash costs per ounce is exclusive of exploration costs. As well, the Company excludes mark-to-market adjustments for the revaluation of previously issued share-based compensation, therefore, total cash costs will incorporate the cost of long term incentives associated with the grant date fair value instruments issued.

(1)Corporate and administrative expenses exclude expenses incurred at development properties.

(2)Comparative figures reflect the inclusion of the Magino Mine as of its acquisition on July 12, 2024.

(3)Share-based compensation included in total cash costs and AISC excludes the impact of mark-to-market adjustments for changes in the Company’s share price in the periods allocated to sites (included in mining and processing costs) and corporate head office (included in share-based compensation expense). The prior year comparatives have been restated to exclude the impact. See Note 13 (d) of the condensed interim consolidated financial statements for further details.

(4)Sustaining capital expenditures are defined as those expenditures which do not increase annual gold ounce production at a mine site and exclude all expenditures at growth projects and certain expenditures at operating sites which are deemed expansionary in nature. Total sustaining capital expenditures for the periods are as follow:

(1)Share-based compensation included in mine-site total cash costs and mine-site AISC excludes the impact of mark-to-market adjustments for changes in the Company’s share price in the periods allocated to sites included in mining and processing costs.

•Earnings from operations - represents the amount of earnings before net finance expense/income, foreign exchange loss/gain, other loss, unrealized loss on commodity derivatives and income tax expense

(Unaudited - stated in millions of United States dollars, except share and per share amounts)

Alamos is a Canadian-based intermediate gold producer with diversified production from three operations in North America. This includes the Island Gold District (comprising the Island Gold and Magino mines) and Young-Davidson mine in Northern Ontario, Canada and the Mulatos District (comprising the Mulatos and La Yaqui Grande mines) in Sonora State, Mexico. Additionally, the Company has a strong portfolio of growth projects, including the Phase 3+ Expansion at Island Gold, the Lynn Lake project in Manitoba, Canada and the Puerto Del Aire (“PDA”) project in the Mulatos District. Alamos employs more than 2,400 people and is committed to the highest standards of sustainable development.

The Company’s common shares are listed on the Toronto Stock Exchange (TSX: AGI) and the New York Stock Exchange (NYSE: AGI). Further information about Alamos can be found in the Company’s regulatory filings, including the Company's Annual Information Form, available on SEDAR+ at www.sedarplus.ca, on EDGAR at www.sec.gov, and on the Company’s website at www.alamosgold.com.

(1)Cost of sales includes mining and processing costs, royalties, and amortization expense.

(2)Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this MD&A for a description and calculation of these measures.

(3)Sustaining finance leases at Island Gold District are not included as additions to mineral property, plant and equipment in cash flows used in investing activities.

(4)Cash and cash equivalents in the comparatives reflect the balance as at December 31, 2024.

(5)Average realized gold price for the three and nine months ended September 30, 2025 included the delivery of ounces into the gold prepayment facility based on the prepaid price of $2,524 per ounce.

(6)Comparative figures reflect the inclusion of the Magino Mine as of its acquisition on July 12, 2024.

(1)Cost of sales includes mining and processing costs, royalties, and amortization expense.

(2)Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this MD&A for a description and calculation of these measures.

(3)For the purposes of calculating mine-site all-in sustaining costs, the Company does not include an allocation of corporate and administrative expense and corporate share-based compensation expense.

(4)Includes capitalized exploration at Island Gold District of $9.6 million and $20.3 million for the three and nine months ended September 30, 2025 ($3.8 million and $10.7 million for the three and nine months ended September 30, 2024 ).

(5)Includes capitalized exploration at Young-Davidson of $4.2 million and $9.1 million for the three and nine months ended September 30, 2025 ($1.5 million and $3.9 million for the three and nine months ended September 30, 2024).

(6)Includes capitalized exploration at Mulatos District of $7.6 million and $10.1 million for the three and nine months ended September 30, 2025 ($0.9 million and $5.9 million for the three and nine months ended September 30, 2024).

(7)The Island Gold District includes Island Gold and Magino mines for the three and nine months ended September 30, 2025. Comparative figures reflect the inclusion of the Magino Mine as of its acquisition on July 12, 2024.

(8)The Mulatos District includes Mulatos and La Yaqui Grande mines.

(9)Sustaining capital expenditures for Island Gold District include certain finance leases classified as sustaining.

•Produced 141,700 ounces of gold, a 3% increase from the second quarter of 2025 reflecting stronger performances from both Mulatos and the Island Gold District. Third quarter production was slightly below the low end of quarterly guidance of 145,000 ounces, reflecting one week of unplanned downtime within the Magino mill due to a capacitor failure within the electrical house, which occurred during the last week of September

•Subsequent to quarter end, a seismic event occurred underground at Island Gold on October 17th. Mining activities continue at budgeted rates; however, this has delayed access to higher grade stopes in one mining front. As a result, grades mined are expected to be lower in the fourth quarter than budgeted. Combined with the unplanned downtime at the end of September at the Magino mill, the Company is updating its 2025 production guidance to a range of 560,000 to 580,000 ounces, a 6% decrease from original guidance (based on the mid-point)

•Fourth quarter production is expected to increase 18% (based on the mid-point) to between 157,000 and 177,000 ounces, the strongest quarter of the year, reflecting a substantial improvement across all three operations

•Generated record free cash flow1 of $130.3 million, while continuing to reinvest in high-return growth projects including the Phase 3+ Expansion, Lynn Lake, and PDA. This was a 54% increase from the second quarter of 2025, reflecting strong contributions from all three operations. At current gold prices, the Company expects strong ongoing free cash flow generation through the remainder of 2025, with significant growth starting in 2026 reflecting higher production and lower costs

•Sold 136,473 ounces of gold at an average realized price of $3,359 per ounce, generating record quarterly revenues of $462.3 million. The average realized gold price was below the London PM Fix price, reflecting the delivery of 12,346 ounces into the gold prepayment facility executed in July 2024 based on the prepaid price of $2,524 per ounce. The Company delivered 75% of the committed ounces under the facility during the first nine months of 2025

•Cash flow from operating activities increased to a record $265.3 million (including $275.3 million before changes in working capital and taxes paid1, or $0.65 per share), a 33% increase from the second quarter of 2025 reflecting strong margin expansion through higher gold prices and lower costs

•Total cash costs1 of $973 per ounce were 9% lower than the second quarter of 2025 and in-line with quarterly guidance. All-in sustaining costs ("AISC")1 of $1,375 per ounce decreased 7% from the second quarter of 2025, driven by the stronger operational performance at the Mulatos District. The Company is reporting total cash costs and AISC excluding the impact of mark-to-market adjustments for the revaluation of previously issued share-based compensation. This provides a better representation of the total costs associated with producing an ounce of gold and eliminates volatility associated with mark-to-market adjustments. Prior year periods have been updated to reflect these changes retrospectively. Mark-to-market adjustments to share-based instruments impact both total cash costs and AISC given the Company allocates these costs to mining and processing costs and share-based compensation expense in the condensed interim consolidated financial statements

•Total cash costs and AISC are expected to decrease 5% in the fourth quarter reflecting higher production and stronger performances from all three operations. The Company remains on track to achieve annual total cash cost and AISC guidance, which was revised in July

•Cost of sales of $194.1 million, or $1,422 per ounce, decreased 4% from the second quarter of 2025 on a per-ounce basis

•Reported net earnings for the quarter were $276.3 million, or $0.66 per share

•Adjusted net earnings1 were $155.5 million, or $0.37 per share. Adjusted net earnings includes net-of-tax adjustments for a reversal of impairment of $192.9 million, and unrealized losses on commodity hedge derivatives of $53.8 million, as well as adjustments for unrealized foreign exchange loss recorded within deferred taxes and foreign exchange loss totaling $15.4 million, and other adjustments of $2.9 million

•Cash and cash equivalents increased 34% from the second quarter of 2025 to $463.1 million at September 30, 2025 reflecting the record free cash flow generation. The Company remains well-positioned to internally fund all of its growth initiatives with strong ongoing free cash flow, net cash of $213.1 million, and $963.1 million of total liquidity

•Announced the sale of the Company's Turkish development projects, which consist of Kirazlı, Ağı Dağı and Çamyurt, to Tümad Madencilik Sanayi ve Ticaret A.Ş (“Tümad”) for total cash consideration of $470 million. The transaction closed in October upon which Alamos received the first payment of $160 million. The remaining cash payments, totaling $310 million are expected to be received on the first and second anniversaries of the closing of the transaction

•Closed the sale of the option to earn 100% interest in the non-core Quartz Mountain Gold Project (“Quartz Mountain”), located in Oregon, to Q-Gold Resources Ltd. (TSXV:QGR) (“Q-Gold”) in October. Quartz Mountain was sold for total consideration of up to $21 million and a 9.9% equity interest in Q-Gold

•With a growing cash balance of more than $600 million following the close of the sale of the Turkish projects and Quartz Mountain, the Company expects to reduce existing debt obligations, and will assess opportunities to be active on its share buyback

•The total recordable injury frequency rate2 ("TRIFR") was 0.97 in the third quarter, compared to 2.01 in the prior year period. For the first nine months of the year, TRIFR was 0.99, compared to 1.86 in the prior year period

•Alamos was recognized for the second consecutive year as a TSX30TM 2025 winner by the Toronto Stock Exchange. The annual ranking recognizes the 30 top performing stocks over a three-year period. Alamos’ share price increased 310% over the trailing three-year period

•Advanced the Phase 3+ Expansion of the Island Gold District. This included the shaft sink progressing to a depth of 1,350 metres ("m") in the third quarter, or 98% of the planned depth. The Phase 3+ Expansion remains on track for completion in the second half of 2026

•Published Alamos’ 2024 Environmental, Social and Governance (“ESG”) Report, outlining the Company’s progress on its ESG performance

(1) Refer to the “Non-GAAP Measures and Additional GAAP Measures” section of this MD&A for a description and calculation of these measures.

(2) Frequency rate is calculated as incidents per 200,000 hours worked.

•TRIFR1 of 0.97 in the third quarter

•Lost time injury frequency rate1 ("LTIFR") of 0.08 in the third quarter

•Alamos had 12 recordable injuries across its sites and one lost time injury in the third quarter

•Year-to-date TRIFR of 0.99 and LTIFR of 0.08

•Five reportable spills occurred in the third quarter

•One reportable effluent exceedance

•Continued reclamation activities at Mulatos for the Cerro Pelon, El Victor and San Carlos pits

•Cash donations to the Haileybury and New Liskeard food banks

•Committed CAD$43,000 to the Blanche River Health Foundation to support the installation of emergency room waiting clocks at Englehart and Kirkland Lake BRH sites, providing accurate and timely information to patients

•Provided new fitness equipment for the Elk Lake Recreation Centre to promote community wellbeing

•Sponsorship of multiple events and teams, including the Canadian Mining Games

•Supported student development through the Young Mining Professionals Scholarships initiative

•Ongoing support within the Mulatos District, including medical services, road maintenance, water distribution, and student scholarships

•The Mulatos District was awarded the prestigious Silver Helmet trophy for excellence in health and safety, for the third time since 2022, recognizing its outstanding management systems and performance

•Released the 2024 ESG Report, highlighting progress on ESG performance across the Company's operations, projects and offices

•Completed annual submissions to the Carbon Disclosure Project and S&P Global’s Corporate Sustainability Assessment, outlining ESG and climate performance

(1) Frequency rate is calculated as incidents per 200,000 hours worked.

On September 14, 2025, the Company announced that its wholly owned Netherlands subsidiaries, Alamos Gold Holdings Coöperatief U.A. and Alamos Gold Holdings B.V. (the “Netherlands Subsidiaries”), had entered into a definitive agreement to sell Doğu Biga Madencilik Sanayi ve Tic. A.Ş., their wholly owned Turkish subsidiary, which owns the Kirazlı, Ağı Dağı and Çamyurt projects located in northwestern Türkiye, to Tümad, a mining company operating in the Republic of Türkiye, for total cash consideration of $470 million (the “Purchase Price”) (the “Transaction”). The Purchase Price is payable by Tümad to Alamos as follows:

i.$160 million payable upon closing of the Transaction;

ii.$160 million payable on the one-year anniversary of the closing of the Transaction (“Second Installment”); and

iii.$150 million payable on the two-year anniversary of the closing of the Transaction (“Third Installment”).

Each of the Second and Third Installment payments is secured by a bank guarantee provided by international financial institutions with investment grade ratings, ensuring total guaranteed proceeds to Alamos of $470 million within two years of closing of the Transaction.

The Transaction closed on October 27, 2025 upon which Alamos received the first cash payment of $160 million and the bank guarantees.

In conjunction with the Transaction, the Netherlands Subsidiaries and the Republic of Türkiye have agreed that arbitration proceedings brought by the Netherlands Subsidiaries against the Republic of Türkiye under the Netherlands-Türkiye Bilateral Investment Treaty (the "Treaty") shall remain suspended, and will be discontinued with prejudice after certain contractual milestones are reached.

On October 22, 2025, the Company closed the sale of the option to earn a 100% interest in Quartz Mountain to Q-Gold for total consideration of up to $21 million and a 9.9% equity stake in Q-Gold. On closing, the Company received $2.85 million in cash and was issued 13.9 million common shares of Q-Gold, resulting in Alamos holding 9.9% of the issued and outstanding common shares of Q-Gold. The remaining consideration of up to $18.15 million will be payable in cash or common shares of Q-Gold, at Alamos’ election, and is comprised of $8.15 million of guaranteed payments to be paid over three years, and $10 million of milestone payments.

On August 8, 2025, the Company filed a base shelf prospectus (the “Base Shelf Prospectus”) with the Ontario Securities Commission, relying on the well-known seasoned issuer exemption, and a corresponding shelf registration statement with the United States Securities and Exchange Commission (the “SEC”) on Form F-10 (the “Registration Statement”). The Base Shelf Prospectus qualifies the issuance of up to US$500,000,000 (or the equivalent in other currencies) of Class A common shares, debt securities, warrants and subscription receipts (collectively, the “Securities”) of the Company, or any combination thereof, in all of the provinces and territories of Canada, and the Registration Statement registers the Securities for offers and sales in the United States using the multijurisdictional disclosure system. The Base Shelf Prospectus is effective for a period of 25 months. The Registration Statement is effective for the duration of the Base Shelf Prospectus.

The Base Shelf Prospectus replaces the previous Base Shelf Prospectus that was filed in May 2023 and expired in June 2025. The Company has filed the Base Shelf Prospectus and Registration Statement to maintain financial flexibility but has no present intentions to undertake an offering of securities under the Base Shelf Prospectus.