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AGI.TO ·

Alamos Gold Extends High-Grade Mineralization Across Multiple Targets within the Island Gold District which Represent Upside as Potential Sources of Additional Higher-Grade Mill Feed

Drill Results

ALAMOS GOLD INC.

Brookfield Place, 181 Bay Street, Suite 3910, P.O. Box #823

Toronto, Ontario, Canada M5J 2T3

Telephone: (416) 368-9932 or 1 (866) 788-8801

All amounts are in United States dollars, unless otherwise stated

F O R I M M E D I A T E R E L E A S E

W E B S I T E : w w w . a l a m o s g o l d . c o m T R A D I N G S Y M B O L : T S X : A G I N Y S E : A G I

Alamos Gold Extends High-Grade Mineralization Across Multiple Targets within

the Island Gold District which Represent Upside as Potential Sources of

Additional Higher-Grade Mill Feed

Toronto, Ontario (June 22, 2026) – Alamos Gold Inc. (TSX:AGI; NYSE:AGI) (“Alamos” or the

“Company”) today reported new results from underground and surface exploration drilling at the

Island Gold Mine. Exploration drilling has defined high -grade mineralization across multiple

areas which are being targeted as sources of additional higher -grade mill feed within the

expanded Magino mill.

This includes defining a new zone of high -grade mineralization 250 metres (“m”) west of

underground Mineral Reserves and Mineral Resources (Island Gold West Extension ), and

continuing to extend mineralization within the Island West up-plunge area. Given its proximity

to surface, Island West up -plunge can be mined utilizing the ramp, providing further upside

potential in terms of combined underground mining rates. Additionally, the regional exploration

program continues to intersect high-grade gold mineralization at the past-producing Cline-Pick,

and Edwards mines, located seven kilometres (“km”) from the Magino Mill (see Figure 1).

"As outlined in the Expansion Study, the Island Gold District is expected to become one of the

largest and lowest cost gold operations in Canada. Given our ongoing exploration success

within the main Island Gold structure, and across multiple near mine targets, we expect there is

further production growth to come. With multiple higher grade targets being defined within

proximity to the Magino mill, and an expansion underway that will provide more than enough

mill capacity, we see excellent potential to driv e production higher by further increasing the

proportion of higher-grade ore that will be processed within the expanded circuit,” said John A.

McCluskey, President and Chief Executive Officer.

Island Gold West Extension Zone: high-grade mineralization has been intersected within

a newly defined zone measuring approximately 200 by 300 m based on drilling to date.

This new zone is located approximately 250 m to as much as 500 m along strike to the

west of the existing Mineral Reserves and Resources of the Island Gold Deposit, and

south of the Magino deposit. The zone remains open down -plunge and to the west, with

drilling continuing to target extensions of the mineralization. New highlights include1:

• Island West Extension Zone:

• 12.05 g/t Au over 5.20 m (MX26-031) including;

• 36.67 g/t Au over 1.50 m.

• 8.07 g/t Au over 5.60 m (MX26-035W) including;

• 45.90 g/t Au over 0.60 m; and

• 30.20 g/t Au over 0.45 m.

T R A D I N G S Y M B O L : T S X : A G I N Y S E : A G I

2 | ALAMOS GOLD INC

Island West up-plunge: drilling continues to expand high-grade gold mineralization

across multiple zones (C, D1, DN2, G1, G10). Given its proximity to surface, and the ability

to be mined via the ramp system, the Island West up-plunge area represents significant

opportunity to increase c ombined underground mining rates beyond the 3,000 tonnes

per day (“tpd”) that is expected to be mined and skipped to surface via the shaft. This

would support further production growth by increasing the proportion of higher -grade ore to be

processed within the expanded Magino mill. New highlights include2:

• 14.51 g/t Au (4.60 g/t cut) over 5.21 m (850-482-05);

• 4.55 g/t Au (3.95 g/t cut) over 16.05 m (850-472-41);

• 12.56 g/t Au (7.76 g/t cut) over 4.73 m (850-482-08);

• 27.11 g/t Au (8.15 g/t cut) over 1.65 m (790-446-05);

• 18.66 g/t Au over 2.30 m (MX26-036);

• 8.53 g/t Au over 4.32 m (790-460-31); and

• 3.30 g/t Au over 9.71 m (790-460-32).

Island West up-plunge unknown zones: h igh-grade mineralization intersected across

multiple yet to be defined zones in both the hanging wall and footwall (“Unknown

Zones”). Additional drilling will be focused on defining these new zones through further

assessing the geometry and continuity of these zones. New highlights include1:

• 20.94 g/t Au over 5.30 m (850-482-07);

• 30.47 g/t Au over 2.65 m (790-460-41);

• 16.28 g/t Au over 4.60 m (850-482-08);

• 6.66 g/t Au over 7.70 m (850-472-61);

• 17.24 g/t Au over 2.30 m (850-472-76); and

• 7.64 g/t Au over 5.15 m (850-482-07).

Island Gold NS1 and NS4 Zone: high-grade gold mineralization intersected within new

and recently defined hanging wall zones, NS1 and NS4 . These zones are low-cost to

develop, given their proximity to existing infrastructure. The NS1 Zone extends into the

Island West up-plunge target area representing an additional opportunity to access high-grade

ore from the existing ramp system. As exploration on the NS4 zone advances up-plunge, there

is also the potential for this zone to extend into the Island West up plunge area. New highlights

include2:

• NS1 Zone:

• 19.48 g/t Au (7.17 g/t cut) over 11.63 m (850-472-61); and

• 7.70 g/t Au over 5.02 m (1025-492-29).

• NS4 Zone: growing parallel structure 180 m west of NS1 Zone

• 132.90 g/t Au (11.51 g/t cut) over 2.21 m (850-472-76);

• 23.56 g/t Au (12.27 g/t cut) over 3.26 m (850-470-30);

• 19.43 g/t Au (5.13 g/t cut) over 2.97 m (850-470-26);

• 10.18 g/t Au over 3.50 m (850-470-21); and

3 | ALAMOS GOLD INC

• 12.71 g/t Au over 2.64 m (850-470-31).

Cline-Pick Mine regional drilling: continues to extend high -grade gold mineralization

beyond the extent of previous mining and follow ing up on the best hole drilled to date

announced earlier this year which intersected 178.07 g/t Au over 3.54 m (25IGX128). The

targets remain open in multiple directions, including at depth, with the deepest holes

drilled to date down to a vertical depth of only 540 m. The Cline-Pick, and adjacent past

producing Edwards Mine are located within 7 km of the Magino mill and are being targeted as

potential sources of additional higher -grade mill feed within the expanded mill. New highlights

include3:

Cline-Pick Mines:

• 67.93 g/t Au over 3.05 m (26IGX143) including;

• 127.72 g/t Au over 1.35 m.

• 5.63 g/t Au over 10.77 m (26IGX136) including;

• 24.70 g/t Au over 2.12 m.

• 62.20 g/t Au over 0.98 m (25IGX128EXT) including;

• 114.00 g/t Au over 0.38 m; and

• 9.18 g/t Au over 3.55 m including;

• 72.30 g/t Au over 0.43 m.

• 4.70 g/t Au over 11.85 m (26IGX137) including;

• 9.28 g/t Au over 5.65 m; and

• 8.28 g/t Au over 5.05 m including;

• 15.71 g/t Au over 2.60 m; and

• 36.80 g/t Au over 0.79 m;

• 2.93 g/t Au over 14.41 m (26IGX138) including;

• 13.48 g/t Au over 2.07 m; and

• 11.89 g/t Au over 2.45 m (26IGX140) including;

• 50.20 g/t Au over 0.52 m.

Edwards Mine:

• 5.06 g/t Au over 13.60 m (25IGX133) including;

• 35.40 g/t Au over 0.80 m; and

• 5.96 g/t Au over 2.25 m including;

• 10.30 g/t Au over 1.10 m.

88-60 Zone:

• 24.12 g/t Au over 3.88 m (26IGX136) including;

• 63.50 g/t Au over 1.42 m.

1 All reported composite intervals are composite core length, and gold grades are reported as uncut.

T R A D I N G S Y M B O L : T S X : A G I N Y S E : A G I

4 | ALAMOS GOLD INC

2 All reported composite intervals are calculated true width of the mineralized zones. Drillhole composite intervals

reported as “cut” include higher grade samples which have been cut to: Island West (C-zone) and Island Main @

230 g/t Au; B and NS1 Zone @ 90 g/t Au; D1 and G1 zone @ 45 g/t Au; G10 Zone @ 25 g/t Au, NS4 Zone @48 g/t

Au; DN and DN2 @ 35 g/t Au.

3 All reported composite intervals reported as uncut, and composites lengths are reported as core length. True width

is estimated to be 40 -85% of core length unless otherwise indicated. Composites are calculated with a 0.5 g/t cut -

off, maximum internal waste of 4 m, and no minimum length.

New highlight intercepts can be found in Tables 1 and 2, and in Figures 1 to 6 at the end of this

news release.

2026 Exploration Drilling Program

A total of $43 million has been budgeted for exploration at the Island Gold District in 2026, up

from $24 million spent in 2025. A significant focus of the 2025 drilling program at Island Gold

and Magino was on delineation drilling to convert the large Inferred Mineral Resource base to

Mineral Reserves. This program was executed successfully and resulted in a significant

increase in Mineral Reserves at both Island Gold and Magino, which was incorporated into the

Island Gold District Expansion Study announced on February 3, 2026. With the deposit open

laterally and at depth, there is significant potential for further growth in Mineral Reserves and

Resources.

A total of 50,000 m of underground exploration drilling is planned in 2026 with a focus on

defining new Mineral Reserves and Resources in proximity to existing production horizons and

infrastructure. This includes drilling across the strike extent of the main Island Gold deposit (E1E

and C-Zones), as well as within a growing number of newly defined hanging wall and footwall

zones. To support the underground exploration program, 1,090 m of underground exploration

drift development is planned to extend drill platforms on multiple levels.

Additionally, 48,000 m of surface exploration drilling has been budgeted targeting the area

between the Island Gold and Magino deposits, as well as the down -plunge extension of the

Island Gold deposit, below a depth of 1,500 m.

The regional exploration program at the Island Gold District includes 16,000 m of surface drilling.

The focus of the regional program will be following up on high-grade mineralization intersected

in the 2025 drill program at Cline and Pick , which are located approximately 7 km northeast

Magino mill. Drilling will also be completed at the historic Edwards mine, located in proximity to

the Cline and Pick mines with the objective of extending mineralization beyond historically

mined areas. Additionally, drilling will be completed at the Island Gold North Shear target, and

to the east and along strike from the Island Gold mine to test the extension of the E1E-zone.

As of June 1 , 2026, a total of 17,760 m of underground drilling was completed in 66 holes.

Additionally, 13,023 m of surface exploration drilling has been completed in 17 holes focused

on expansion of Island Gold to the east, west, and down -plunge. As part of the regional

exploration program, 8,123 m of drilling has been completed in 13 holes and two extension

holes.

The focus of this press release is on the variety of higher-grade upside opportunities that are

being targeted beyond the main Island Gold underground structure. Ongoing success within the

main structure is expected to support further growth in Mineral Reserves and Resources as

drilling continues to advance across multiple areas, including Island East and down-plunge.

Results from drilling within the main structure are expected to be released later in 2026.

5 | ALAMOS GOLD INC

Island Gold West Extension

High-grade mineralization was intersected in a new zone from seven holes (six surface and one

underground), spaced approximately 40 m to 100 m apart. Assays are pending from four of the

surface holes. This new zone is located 300 m along strike to the west of the current Island Gold

Mine Mineral Reserves and Resources, and has currently been tested between 750 and 1,000

m from surface. Based on the initial drilling this new zone has been defined over an exten t of

approximately 200 m by 300 m and is open to the west and down -plunge. This zone is in an

area that has seen very limited exploration, to the west of the “Creek Fault”, south of the Webb

Lake Stock, and the Magino deposit. Only one historic hole (AR-390-01) was completed in this

target area by Alamos in 2018, which intersected 7.03 g/t over 5.50 m including 38.74 g/t Au

over 0.70 m, and was classified as an “Unknown” zone at that time.

Drilling will continue in this area from both surface and from underground drill platforms

established in the western portion of the Island Gold Mine on the 490 and 790-levels.

New highlights include1 (Figure 2, Table 1):

• Island West Extension Zone:

• 12.05 g/t Au over 5.20 m (MX26-031) including;

• 36.67 g/t Au over 1.50 m.

• 8.07 g/t Au over 5.60 m (MX26-035W) including;

• 45.90 g/t Au over 0.60 m; and

• 30.20 g/t Au over 0.45 m.

1 All reported composite intervals are composite core length, and gold grades are reported as uncut.

Island West Up-Plunge

The Island West up-plunge area represents significant opportunity to support increased

underground mining rates beyond the 3,000 tpd that is expected to be skipped to surface via

the shaft. Given its proximity to surface, this area can be mined via the ramp system providing

higher combined underground mining rates . This would increase the proportion of high -grade

ore processed within the expanded Magino mill, supporting higher combined gold production .

Surface and underground exploration drilling in 2026 has been focused on expanding high-

grade gold mineralization within the Island West up-plunge area in multiple zones (C, D1, DN2,

G1, G10) from 400 to 900 m below surface. Drilling remains focused on continuing to define

additional high-grade mineralization in this area, up-plunge towards surface.

New highlights include2 (Figure 2, Table 1):

• 14.51 g/t Au (4.60 g/t cut) over 5.21 m (850-482-05);

• 4.55 g/t Au (3.95 g/t cut) over 16.05 m (850-472-41);

• 12.56 g/t Au (7.76 g/t cut) over 4.73 m (850-482-08);

• 27.11 g/t Au (8.15 g/t cut) over 1.65 m (790-446-05);

• 18.66 g/t Au over 2.30 m (MX26-036);

• 8.53 g/t Au over 4.32 m (790-460-31); and

• 3.30 g/t Au over 9.71 m (790-460-32).

T R A D I N G S Y M B O L : T S X : A G I N Y S E : A G I

6 | ALAMOS GOLD INC

In addition, multiple high-grade intervals were intersected in the hanging wall and footwall of the

Island West up-plunge area within yet to be defined zones. Additional drilling will be focused on

defining new zones through further assessing their geometry and continuity.

New highlights from “Unknown zones” in the Island West up plunge area include1 (Table 1):

• 20.94 g/t Au over 5.30 m (850-482-07);

• 30.47 g/t Au over 2.65 m (790-460-41);

• 16.28 g/t Au over 4.60 m (850-482-08);

• 6.66 g/t Au over 7.70 m (850-472-61);

• 17.24 g/t Au over 2.30 m (850-472-76); and

• 7.64 g/t Au over 5.15 m (850-482-07).

1 All reported composite intervals are composite core length, and gold grades are reported as uncut.

2 All reported composite intervals are calculated true width of the mineralized zones. Drillhole composite intervals

reported as “cut” include higher grade samples which have been cut to: Island West (C-zone) and Island Main @

230 g/t Au; B and NS1 Zone @ 90 g/t Au; D1 and G1 zone @ 45 g/t Au; G10 Zone @ 25 g/t Au, NS4 Zone @48 g/t

Au; DN, DN2 @ 35 g/t Au.

Island West Hanging Wall NS-Zones

In addition to testing the main Island Gold structure (C -Zone), underground exploration drilling

continued to target high-grade gold mineralization in sub -parallel and perpendicular structures

in the hanging wall from the 850 and 1025-levels.

NS Hanging Wall Zones

The NS1 zone is a northwest -striking structure with a high -angle orientation relative to the C -

Zone that was discovered in early 2023. The first stopes were mined from the NS1 zone during

the second half of 2023, and it continues to be actively mined, high lighting the size and near-

term opportunities within these hanging wall and footwall zones. Notably, the NS1 Zone extends

into the Island West up-plunge target area representing an additional opportunit y to access

high-grade ore from the existing ramp system.

The NS4 zone is a northwest -striking structure discovered in 2024, 180 m west of and

subparallel to the NS1 zone. To date, this zone has been defined over a vertical extent of 400

m, and an average strike of 300 m. As exploration on the NS4 zone advances up-plunge, there

is also the potential for the NS4 zone to extend into the Island West up plunge area. Several

other north -striking high -angle structures have been identified across the deposit from

reinterpretation of historical hanging wall drilling, incl uding the NS2 and NS3 zones which will

be further drill tested in 2026 . These structures will continue to be further evaluated as

underground exploration drilling advances, and represent significant opportunities to continue

to grow near mine Mineral Reserves and Resources which are low-cost to develop, given their

proximity to existing infrastructure.

New highlights from the Island West Hanging Wall zones include2 (Table 1, Figure 2):

• NS1 Zone:

• 19.48 g/t Au (7.17 g/t cut) over 11.63 m (850-472-61); and

• 7.70 g/t Au over 5.02 m (1025-492-29).

• NS4 Zone: growing parallel structure 180 m west of NS1 Zone

• 132.90 g/t Au (11.51 g/t cut) over 2.21 m (850-472-76);

7 | ALAMOS GOLD INC

• 23.56 g/t Au (12.27 g/t cut) over 3.26 m (850-470-30);

• 19.43 g/t Au (5.13 g/t cut) over 2.97 m (850-470-26);

• 10.18 g/t Au over 3.50 m (850-470-21); and

• 12.71 g/t Au over 2.64 m (850-470-31).

2 All reported composite intervals are calculated true width of the mineralized zones. Drillhole composite intervals

reported as “cut” include higher grade samples which have been cut to: Island West (C-zone) and Island Main @

230 g/t Au; B and NS1 Zone @ 90 g/t Au; D1 and G1 zone @ 45 g/t Au; G10 Zone @ 25 g/t Au, NS4 Zone @48 g/t

Au; DN, DN2 @ 35 g/t Au.

Regional Exploration

Cline-Pick, and Edwards Mines, and 88-60 Zone

The Cline-Pick and Edwards (“CEP”) mines are located 7 km by road northeast of the Magino

mill (Figures 3 and 4). Alamos acquired these past -producing mines in 2020 as part of its

consolidation of the northeastern segment of the Michipicoten Greenstone Belt with the

acquisition of Trillium Mining Corp.

Since 2023, Alamos has completed 19,448 m of drilling in 56 holes at CEP as part of the regional

drilling program. The 2026 regional exploration program includes 12,500 m focused at CEP with

the objective of advancing the deposits towards a Mineral Resource estimate.

Drilling completed year to date continues to expand high-grade gold mineralization beyond the

extent of historic mining . Extension of high -grade gold mineralization at these historic mines

represent potential future sources of additional higher-grade ore within the expanded Magino

mill.

The focus of the 2026 Cline -Pick drill program has been to follow up on drill hole 25IGX128

which returned 178.07 g/t Au over 3.54 m (see press release dated February 2, 2026) . Drill

hole 25IGX128, had targeted a 300 m gap in drilling, approximately 430 m from surface, where

a moderate east plunging ore shoot is associated with a subvertical east -west trending shear

zone. The vein has been interpreted as a moderate-steeply dipping shear-vein, with true width

estimated at approximately 50% of core length.

Step out drilling is being completed within the shear zone at 40 to 75 m spacing, with the focus

on further defining the geometry and orientations of both the shear and the veins, as well as

determining the controls on gold mineralization. These holes represent some of the deepe r

holes drilled at Cline-Pick, intersecting the target zone down to a 510 m vertical depth, and the

main structure remains open at depth and along strike.

New highlights include3 (Figure 5 and 6, Table 2):

Cline-Pick Mines:

• 67.93 g/t Au over 3.05 m (26IGX143) including;

• 127.72 g/t Au over 1.35 m.

• 5.63 g/t Au over 10.77 m (26IGX136) including;

• 24.70 g/t Au over 2.12 m.

• 62.20 g/t Au over 0.98 m (25IGX128EXT) including;

• 114.00 g/t Au over 0.38 m; and

• 9.18 g/t Au over 3.55 m including;

T R A D I N G S Y M B O L : T S X : A G I N Y S E : A G I

8 | ALAMOS GOLD INC

• 72.30 g/t Au over 0.43 m.

• 4.70 g/t Au over 11.85 m (26IGX137) including;

• 9.28 g/t Au over 5.65 m; and

• 8.28 g/t Au over 5.05 m including;

• 15.71 g/t Au over 2.60 m; and

• 36.80 g/t Au over 0.79 m;

• 2.93 g/t Au over 14.41 m (26IGX138) including;

• 13.48 g/t Au over 2.07 m; and

• 11.89 g/t Au over 2.45 m (26IGX140) including;

• 50.20 g/t Au over 0.52 m.

Edwards Mine:

Two drill holes were also completed to the northeast of the Edwards Mine Shaft #1, testing for

the potential extension of mineralization. Both holes intersected gold mineralization with the

high-grade highlight in drill hole 25IGX133 which returned 5.06 g/t Au over 13.60 m, including

35.40 g/t Au over 0.80 m. Additional drilling will be completed in the second half of the 2026

following up on this drill hole. New highlights include:

Edwards Mine:

• 5.06 g/t Au over 13.60 m (25IGX133) including;

• 35.40 g/t Au over 0.80 m; and

• 5.96 g/t Au over 2.25m including;

• 10.30 g/t Au over 1.10 m.

88-60 Zone:

Surface drilling targeting Cline -Pick at depth also intersected high -grade mineralization in the

88-60 zone which is located approximately 200 m north of Cline-Pick (see Figure 4). Drill hole

26IGX136 intersected 24.12 g/t Au over 3.88 m , including 63.50 g/t Au over 1.42 m , at a

vertical depth of only 67 m from surface. The last exploration drilling program targeting the 88-

60 zone in 2023 also intersected high -grade mineralization. This included 6.00 g/t Au over

11.18 m, including 19.79 g/t over 1.12 m, 20.90 g/t over 0.78 m, and 24.60 g/t over 0.58 m

in drill hole 23IGX066, at a vertical depth of only 113 m (see press release dated November 9,

2023). New highlights include:

88-60 Zone:

• 24.12 g/t Au over 3.88 m (26IGX136) including;

• 63.50 g/t Au over 1.42 m.

3 All reported composite intervals reported as uncut, and composites lengths are reported as core length. True width

is estimated to be 40 to 85% of core length unless otherwise stated. Composites are calculated with a 0.5 g/t cut-off,

maximum internal waste of 4 m, and no minimum length.

Qualified Persons

Scott R.G. Parsons, P.Geo., FAusIMM, Alamos Gold’s Senior 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.