Investor Update - March 2026

Corporate Update

March 2026

Uranium Development & Exploration

The Athabasca Basin, Northern Saskatchewan

#1 Non-Precious Mining

Development Project

in the World

Advanced Athabasca Basin uranium developer with unique asset mix

• Phoenix, Gryphon, Midwest and THT/Waterbury all projected within UxC's "First Tier" of global assets(2)

  #1 Phoenix combines lowest-cost mining method with Athabasca Basin high-grades

• Ranked #1 non-precious mining development project globally in 2025 by Mining Journal Intelligence

• Construction planned to commence in March 2026 for flagship In-Situ Recovery ('ISR') mine(3)

• Final Investment Decision made shortly after regulatory approvals received to commence construction(3,4)

• Technical de-risking completed; C$47M spent on long-lead procurement(5,6)

• First production targeted by mid 2028(6)

  
  
  Ownership interest in strategic regional asset with McClean Lake mill and producing mine

• Excess licensed milling capacity, with approval for expanded tailings management facility

• 2025 mining restart at McClean North deposit announced by Orano Canada

  High-potential exploration portfolio and interests in key mines / projects operated by "majors"

• Large Athabasca Basin exploration portfolio, including Moon Lake South and Johnston Lake properties

• Minority interests in Cameco-JCU's Millennium project and Orano-JCU's Kiggavik project

  
  
  Strong balance sheet with ~C$718M in cash, physical uranium and investments(7)

• Denison's financial and liquid assets on hand, relative to initial capex(6) for the flagship Phoenix development project

(C$570M for Denison's effective 95% interest) puts the company in a strong position

3

NOTES: (1) See supporting slides for details. (2) UxC's Uranium Production Cost Study dated Aug. 2025. (3) See news release dated Feb. 24, 2026. (4) See news release dated Feb. 19th, 2026. (5) The amount spent on long lead procurement is a non-GAAP measure and reflects spend on items reported in property plant and equipment as of Nov. 30, 2025. (6) See news release dated Jan. 2, 2026. (7) As of Sep. 30, 2025. For additional details see financial statements and MD&A for the period ended Sep. 30, 2025. (8) World Nuclear News article dated Nov. 17, 2025.

Multi-asset leverage to uranium market from advanced + diversified Athabasca Basin asset base

NOTES:.

1. Denison's effective interest

   held directly and 5% held

   in Wheeler River includes 90%

   indirectly through its 50%

   Exploration Company,

   ownership of JCU (Canada) Limited.

   Feb. 24, 2026.

2. See news release dated

   (4) Derived from UxC's

   (3) Phoenix Project - See news

   release dated Feb 19, 2026 Uranium Market Outlook

   dated Q4'2025

   (5) See news release dated Jul. 17, 2025.

   (6) See news release dated

   Aug. 6, 2025.

   (7) Refer to the Waterbury

   Lake Technical Report titled

   Assessment for the Tthe

   "Preliminary Economic

   Northern Saskatchewan,

   Heldeth Túé (J Zone) Deposit,

   Waterbury Lake Property,

   Canada" dated Oct. 30, 2020.

   1. See news release dated

      Nov. 6, 2023.

   2. See news release dated

   Aug. 3, 2021.

   (10) Denison direct land

   positions held by JCU.

   position shown as of Dec. 17, 2025; excludes the land

   4

   
   
   Denison's Development Portfolio Projects:

   Four assets amongst the lowest all-in cost assets of UxC's First Tier

   Sample of Global Production Costs - August 2025(1)(2)(3)(4)

   Planned and Producing Operations (with Mining Method)

   UxC's "First Tier"

   (includes lowest-cost projects with full costs up to ~US$37.50/lb U3O8)

   "Second Tier"

   (up to ~US$50.01/lb U3O8)

   "Third/Fourth Tier"

   (up O )

   to ~US$97.51/lb U3

   8

   $18.41 (2026)(2)

   $24.93 (2020)

   $25.47 (2023)

   $25.78

   (2025)

   
   
   

   $80

   All-in / Full Costs - USD$/lb U3O8

   $70

   $60

   $50

   $40

   $30

   ISR ISR ISR

   ISR UG

   UG

   UG UG ISR

   UG ISR UG

   ISR

   $20

   UG OP OP OP ISR ISR ISR OP

   OP

   $10

   $0

   
   
   
   
   Denison/Canada (Technical Reports)
   
   

   Denison/Canada (UxC Est.)

   Canada

   Kazakhstan

   Australia

   1. Africa

      ISR: In-Situ Recovery UG: Underground OP: Open Pit

      NOTES:

      1. Chart data, including "full costs" and UxC's categorization of

         production cost "tiers", have been derived from UxC's estimates of worldwide production costs from the Uranium Production Cost Study dated Aug. 2025.

      2. For Phoenix and Gryphon, see the Wheeler River Technical Report titled "NI 43-101 Technical Report on the Wheeler River Project, Athabasca Basin, Saskatchewan, Canada" dated Jun. 23, 2023 and Denison's news release on Jun. 26, 2023. Phoenix all-in costs reflects updated initial

         capital, refer to Denison's news release dated Jan. 2, 2026

      3. For THT/Waterbury, refer to the Waterbury Lake Technical Report titled "Preliminary Economic Assessment for the Tthe Heldeth Túé (THT) (J Zone) Deposit, Waterbury Lake Property, Northern Saskatchewan, Canada" dated Oct. 30, 2020 and Denison's news release on Nov. 17, 2020.

      4. For Midwest, refer to Denison's news release dated Aug. 6, 2025.

      5

      
      
      

      Large land position in the infrastructure-rich

      eastern portion of the Athabasca Basin(1)

Midwest (Denison 25.17%)

Waterbury Lake (Denison 70.55%)

McClean Lake Mill

(Denison 22.5%)

McClean Lake North

(Denison 22.5%)

Moon Lake South (Denison 75%)

All Season Highway

/ Haul Road

Waterfound (Denison 24.68%)(2)

Johnston Lake (Denison 100%)

McArthur River Mine

Provincial Power Grid

Key Lake Mill

Rabbit Lake Mill

Cigar Lake Mine

NOTES:

debt drawn as of Sept. 30,

as more fully described in the

2025; however, the company has a letters of credit facility in place that is used to secure reclamation letters of credit,

MD&A for the period ended

financial statements and Sept. 30, 2025.

7

95% owned flagship Wheeler River project(1)(2)

Potential to deliver meaningful production when the market needs It

NOTES:

(1) Refer to the Wheeler

Report on the Wheeler

River Technical Report

titled "NI 43-101 Technical

River Project, Athabasca

Canada" dated Jun.

(2) Denison increased its

Basin, Saskatchewan, 23, 2023.

effective interest in

Wheeler River as part of

the acquisition of 50% of

Company, Limited. See

JCU (Canada) Exploration

Denison's news release

dated Aug. 3, 2021.

1. Reflects 10-year mine life estimated for Phoenix and 6.5-year mine life

   estimated for Gryphon.

2. See news release dated

   Feb. 24, 2026.

3. See news release dated

   Feb 19, 2026.

4. See news release dated

Aug. 5, 2025.

(7) See news release

dated Jan. 2, 2026.

dated Oct. 17, 2022 and

(8) See news releases Nov. 22, 2022.

8

Reflects rigour of multi-year technical de-risking and delivers impressive economic results

PHOTOS:

Phoenix Feasibility Field Test (FFT) facilities during operations in 2022.

NOTES:

1. See the Wheeler River Technical Report titled "NI 43-101 Technical Report on

   the Wheeler River Project, Athabasca Basin, Saskatchewan,

   Canada" dated Jun. 23, 2023.

2. See news release dated Jan. 2, 2026.

3. Mining Journal Project Pipeline Handbook 2025.

4. NPV and IRR are calculated to the start of construction activities for the Phoenix operation and excludes $100 million in pre-FID expenditures. Post-tax NPV, IRR and payback period are based on the "adjusted Post-tax" scenario, which includes the benefit of entity level tax attributes which are expected to be available and used to reduce taxable income from the Phoenix operation. See Jan. 2, 2026 press release for further details.

5. All-in cost is estimated on a pre-tax basis and includes all project operating costs, capital costs post-FID, and decommissioning costs divided by the estimated number of pounds U3O8to be produced. Includes updated initial capital costs (2026). See Wheeler River Technical Report and Denison's news release dated Jan. 2 2026 for details.

9

Optimized production profile based on detailed ISR mine planning efforts

NOTES: (1) Refer to the Wheeler River Technical Report titled "NI 43-101 Technical Report on the Wheeler River Project, Athabasca

Basin, Saskatchewan, Canada" dated Jun. 23, 2023; (2) Refer to the press release titled "Denison Reports Readiness to Commence Construction of Flagship Phoenix ISR Project and Provides Capital Cost Update" dated Jan. 2, 2026; (3) See press release Feb. 24, 2026; (4) NPV and IRR are calculated to the start of construction activities for the Phoenix operation and excludes $100 million in pre-FID expenditures; (5) Payback period

is stated as number of months to payback from the start of uranium production. 10

Phoenix Construction to Commence March 2026

De-risking complete and project is construction-ready

Significant

De-risking and Engineering to Position for Execution

• High-grade, low-cost project justified technical studies and extensive test work, detailed engineering, permitting + team building during period prior to improved uranium market

• Total engineering ~87% complete, including most scopes planned for the first year of construction at 100% total engineering(1,2)

• Grid power available, with new SaskPower line completed to Phoenix(3)

• Construction management contract awarded to Wood Canada Limited(4)

Leading Permitting & Community Engagement

• Final Federal regulatory approval received to construct the Phoenix ISR Uranium Mine, with CNSC approval of the EA, and Licence to Prepare Site and Construct a Mine and Mill (5)

• Received Saskatchewan EA approval for Phoenix, harmonized with federal EA and CNSC approval(5)

• Multiple impact-benefit type agreements with Indigenous nations and northern communities, plus leading engagement practices(7)

  Advanced Procurement & Construction Mobilization

• Teams Mobilizing to Begin Construction with the procurement process for planned 2026 construction nearly complete and remaining contract awards pending and expected in early 2026(2)

• Final Investment Decision completed with construction anticipated to commence immediately(8)

• Project timeline on track for targeted first production by mid-2028

  Robust Balance Sheet

• Strong Balance Sheet to fund construction with ~CAD$718M

  in cash, physical uranium and investments(1)

• Physical uranium holdings intended to support project financing and offer significant financial flexibility(1)

PHOTO:

View of new SaskPower 138kV Transmission Line to the site of the Future Phoenix Uranium Mine.

NOTES:

1. For additional details see financial statements and MD&A for the period ended Sept. 30, 2025.

2. See news release dated Jan. 2, 2026.

3. See news release dated Jan. 8 2026.

4. See news release dated Feb. 17, 2026

5. See news release

   dated Feb. 19, 2026

6. See news releases dated Aug. 5, 2025.

7. See news releases dated Sept. 27, 2023, Jul.

   11, 2024, and Oct. 20,

   2022, and MD&A for the period ended Dec. 31,

   Commercial Strategy Aligned with Project Financing Objectives and Asset Base

   • Active engagement with future customers for potential commercial contracting

   • Multiple sources of supply is a differentiator: Physical U3O8, McClean Lake North production, & future Phoenix production

     2022.

8. See news releases

dated Feb, 24, 2026.

11

Provides Denison with additional source of low-cost production to reinvest Phoenix cash flows(1)

PHOTO:

View inside the SX circuit at Denison's 22.5% owned McClean Lake mill, which is assumed to toll mill production from the Gryphon UG operation.

NOTES:

1. See the Wheeler River Technical Report titled "NI 43-101 Technical Report on the Wheeler River Project, Athabasca Basin, Saskatchewan, Canada" dated Jun. 23, 2023.

2. NPV and IRR are calculated to the start of pre-production activities for the Gryphon operation.

3. All-in cost is estimated on a pre-tax basis and includes all project operating costs, capital costs post-FID, and decommissioning costs divided by the estimated number of pounds U3O8to be produced. See Wheeler River Technical Report and Denison's news release dated Jun. 26, 2023 for details.

12

Capital and operating costs updated from 2018 PFS + minor scheduling optimizations

NOTES: (1) Refer to the Wheeler River Technical Report titled "NI 43-101 Technical Report on the Wheeler River Project, Athabasca Basin, Saskatchewan, Canada" dated Jun. 23, 2023; (2) NPV and IRR are calculated to the start of construction activities for the Gryphon operation, and excludes $56.5 million in pre-FID expenditures; (3) Payback period is stated as number of months to payback from the start of uranium production; (4) Post-tax NPV is estimated to be $864.2 million in the Base Case; (5) Post-tax payback period is estimated to be 23 months in the Base-Case; (6) Post-tax IRR is estimated to be 37.6% in the Base Case.

13

Strategic asset uniquely positioned to support new sources of supply from JV owners

PHOTO:

Aerial view of Denison's 22.5% owned McClean Lake mill facility.

NOTES:

1. Per UxC's Q4' 2025

   Uranium Market Outlook and Cameco's management's discussion and analysis dated Feb. 13, 2026.

2. See Denison's news release dated Jan. 19, 2022.

3. Denison monetized its share of tolling revenues from the Cigar Lake toll milling agreement. See Denison's news releases dated Feb. 1, 2017 and

   Feb. 13, 2017. Please also refer to Denison's current Annual Information Form and Financial Statements and Management, Discussion and Analysis for additional details related to the toll milling agreement.

4. See Denison's current Annual Information Form for additional details regarding the McClean Lake mill facility.

14

Mining restart achieved via SABRE mining method at McClean North deposit

PHOTO:

2021 SABRE test mining program in action, with view of specialized mining pipes in inset photo.

NOTES:

1. As of Sept. 30, 2025, 100% basis. See Denison's financial statements and MD&A for the three months ended Sept. 30, 2025 for details.

2. See Denison's current AIF for additional details regarding the McClean Lake deposits and SABRE mining method.

3. See Denison's financial statements and MD&A for the three months ended Sept. 30, 2025 for details.

4. See Denison's current

   AIF for additional details.

5. See Denison's news releases dated Sept. 8, 2022 and Jul. 21, 2025.

15

In-Situ Recovery PEA for Midwest Main leverages high-grades & proximity to McClean mill(1)

PHOTO:

Aerial view of Midwest Project.

NOTES:

1. See Denison's news release dated Aug. 6, 2025.

2. See Denison's current Annual Information Form for additional details regarding the Midwest project.

3. NPV and IRR are calculated to the start of construction activities for the Midwest project and excludes the C$16.8M in pre-FID expenditures.

4. All-in cost is estimated on a pre-tax basis and includes all project operating costs, capital costs post-FID, and decommissioning costs divided by the estimated number of pounds U3O8to be produced.

16

Demonstrates economic and technical potential at the Midwest Main deposit

7,000,000

6,000,000

Pounds U3O8per year

5,000,000

4,000,000

3,000,000

Midwest mine production per year

2,000,000

1,000,000

-

Calendar Years

Production lbs U3O8

1 2 3 4 5 6 7

6.1M 6.1M 6.1M 6.1M 6.1M 6.1M 0.8M

NOTES: (1) Refer to Denison's news release dated Aug. 6, 2025; (2) NPV and IRR are calculated to the start of construction activities for the Midwest project and excludes $16.8 million in pre-FID expenditures; (3) Payback period is stated as number of months to payback from the start of uranium production; (4) Post-tax NPV is estimated to be $964.7.2 million in the Base Case; (5) Post-tax payback period is estimated to be ~9 months in the Base-Case; (6) Post-tax IRR is estimated to be 82.7% in the Base Case.

17

PEA (2020) shows potential for ISR to change uranium mining landscape in Canada(1)

PHOTOS:

Aerial rendering of surface facilities for the THT ISR operation

NOTES:

1. Refer to the Waterbury Lake Technical Report titled "Preliminary Economic Assessment for the Tthe Heldeth Túé (J Zone) Deposit, Waterbury Lake Property, Northern Saskatchewan, Canada" dated Oct. 30, 2020.

2. See Denison's news

release dated Nov. 6, 2023

1. All-in cost is estimated on a pre-tax basis and includes all project operating costs and capital costs divided by the estimated number of finished pounds U3O8produced.

2. NPV and IRR are calculated based on assessed "high-case" uranium price, to the start of pre-production activities.

3. Post-tax NPV attributable to Denison's then 66.90% interest is estimated to be between

   $72 million (base-case) and $109 million ($65/lb high-case).

4. Post-tax IRR attributable to Denison's then 66.90% interest is estimated to be between 30.4% (base-case) and

38.9% ($65/lb high-case).

18

Strengthening exposure to exploration upside through strategic investment

(9) As of September 30, 2025. See Denison's Q3 2025 MD&As for more information. 19

Fundamental considerations driving Denison's operations

PHOTO:

Highlights of the Elders of Sakitawak's market garden in Ile a la Crosse, a community-based initiative sponsored by Denison.

NOTES:

1. See news release dated Dec. 2, 2021.

2. For more information: https://www.theglobeand mail.com/business/career s/management/board-games/article-canada-corporate-boards-ranking-2025/

3. See Denison's news release dated Mar. 15, 2021.

4. See news release dated Sep. 27, 2023.

5. See news release dated Jul. 11, 2024.

6. See news release dated Dec. 1,2025.

7. See news release dated Dec. 4 2025.

8. See Denison's AIF for additional details.

**includes the Hatchet Lake Denesułiné First Nation, Black Lake Denesułiné First Nation, Fond du Lac Denesułiné First Nation, the Northern Hamlet of Stony Rapids, the Northern Settlement of Uranium City, the Northern Settlement

of Wollaston Lake, and the Northern Settlement of Camsell Portage

20

World