NexGen Files Management Information Circular in Connection with Annual General and Special Meeting of Shareholders

NexGen Files Management Information Circular in Connection with

Annual General and Special Meeting of Shareholders

Vancouver, BC, May 21, 2025 – NexGen Energy Ltd. (“NexGen” or the “Company”) (TSX: NXE, NYSE MKT:

NXE, ASX:NXG) is pleased to announce it has mailed a Notice of Meeting and Management Information Circular

to Shareholders of record as of Monday, May 11, 2026 in connection with the Annual General and Special Meeting

of the Company to be held on Tuesday, June 30, 2026, at 2:00 p.m. (Pacific Time).

Your Vote is Important - Please Vote Today.

Shareholders are encouraged to read the meeting materials including the Management Information Circular that

provides a detailed analysis of important considerations for voting at the meeting. These materials have been filed

on SEDAR+ (www.sedarplus.ca) and can be found on our website under NexGen Investor Centre – Reports and

Filings: https://www.nexgenenergy.ca/investor-center/

Shareholders will be asked to vote on the following matters:

1. Elect directors for the ensuing year;

2. Appoint PricewaterhouseCoopers (PWC) as independent auditor of the Company for the 2026 financial

year and to authorize the directors to fix their remunerations;

3. Approve the continuation, amendment, and restatement of the Company’s Shareholder Right’s plan ; and

4. Set the number of directors at nine;

The Board of Directors of NexGen recommends that Shareholders vote in favour of all proposed items.

Meeting Access and Location:

Webcast URL: https://app.webinar.net/ZvNRDmB6bPk

Conference Call Dial-In:

To join the conference call by phone, please use the following URL to easily register yourself and be connected

into the conference call automatically or dial direct.

https://emportal.ink/4tymBoT

Conference ID: 75646

North American Toll Free: 1-888-699-1199

Australia: 61-280-171-385

Location: NexGen Energy Ltd. Corporate Office

Suite 3150, 1021 West Hastings St.

Vancouver, BC Canada

Participants of the webcast and conference call will be able to participate in the Q&A session following the formal

business of the Meeting and presentation.

How to Vote

Non-Registered Shareholders

Shares held with a broker, bank or

other intermediary

(16-digit control number)

Registered Shareholders

Shares held in own name and

represented by a physical

certificate or DRS Statement

(15-digit control number)

CDI Holders

Shares held by way of CDIs through

CHESS Depository Nominees Pty

Limited

www.proxyvote.com www.investorvote.com www.investorvote.com.au

Call or fax to the number(s) listed

on your voting instruction form

Canada 1-800-474-7493 (English)

Or 1-800-474-7501 (French)

USA: 1-800-454-8683

Phone: 1-866-732-8683 Fax to the number(s) listed on your

CDI voting instruction form

Return the voting instruction form in

the enclosed postage paid

envelope

Return the form of proxy in the

enclosed postage paid envelope

Return the CDI voting instruction

form to the address listed in your

CDI voting instruction form

Please submit your vote well in advance of the proxy deposit deadline of

2:00p.m. (Pacific Time) on Friday June 26, 2026.

Shareholder Information and Questions

NexGen shareholders who have questions about the Management Information Circular, or require assistance with

voting their shares can contact the Company’s proxy solicitation agent:

Kingsdale Advisors

North America Toll Free: 1-888-518-1563

Call and Text Enabled Outside North America: 1-437-561-5005

Toll Free In Australia: 1-800-755-963

Email: [email protected]

About NexGen

NexGen Energy is a Canadian company focused on delivering clean energy fuel for the future.   The Company’s

flagship Rook I Project  is being optimally developed into the largest low cost producing uranium mine globally,

incorporating the most elite standards in environmental and social governance.   The Rook I Project is supported

by a NI 43-101 compliant Feasibility Study which outlines the elite environmental performance and industry leading

economics. NexGen is led by a team of experienced uranium and mining industry professionals with expertise

across the entire mining life cycle, including exploration, financing, project engineering and  construction,

operations and closure.  NexGen is leveraging its proven experience to deliver a Project that leads the entire mining

industry socially, technically and environmentally.  The Project and prospective portfolio in northern Saskatchewan

will provide generational long-term economic, environmental, and social benefits for Saskatchewan, Canada, and

the world.

NexGen is listed on the Toronto Stock Exchange, the New York Stock Exchange under the ticker symbol “NXE”

and on the Australian Securities Exchange under the ticker symbol “NXG” providing access to global investors to

participate in NexGen’s mission of sol ving three major global challenges in decarbonization, energy security and

access to power.  The Company is headquartered in Vancouver, British Columbia, with its primary operations office

in Saskatoon, Saskatchewan.

Forward-Looking Information

The information contained herein contains "forward -looking statements" within the meaning of applicable United

States securities laws and regulations and "forward-looking information" within the meaning of applicable Canadian

securities legislation. "Forward -looking information" includes, but is not limited to, statements with respect to

mineral reserve and mineral resource estimates, the 2021 Arrow Deposit, Rook I Project and estimates of uranium

production, grade and long-term average uranium prices, anticipated effects of completed drill results on the Rook

I Project, planned work programs, completion of further site investigations and engineering work to support basic

engineering of the project and expected outcomes. Generally, but not always, forward -looking information and

statements can be identified by the use of words such as "plans", "expects", "is expected", "budget", "scheduled",

"estimates", "forecasts", "intends", "anticipates", or "believes" or the negative connotation thereof or variations of

such words and phrases or state that certain actions, events or results "may", "could", "would", "might" or "will be

taken", "occur" or "be achieved" or t he negative connotation thereof.  Statements relating to "mineral resources"

are deemed to be forward -looking information, as they involve the implied assessment that, based on certain

estimates and assumptions, the mineral resources described can be profitably produced in the future.

Forward-looking information and statements are based on the then current expectations, beliefs, assumptions,

estimates and forecasts about NexGen's business and the industry and markets in which it operates. Forward -

looking information and statements are m ade based upon numerous assumptions, including among others, that

the mineral reserve and resources estimates and the key assumptions and parameters on which such estimates

are based are as set out in this news release and the technical report for the prop erty , the results of planned

exploration activities are as anticipated, the price and market supply of uranium, the cost of planned exploration

activities, that financing will be available if and when needed and on reasonable terms, that third party contractors,

equipment, supplies and governmental and other approvals required to conduct NexGen's planned exploration

activities will be available on reasonable terms and in a timely manner and that general business and economic

conditions will not change in a material adverse manner. Although the assumptions made by the Company in

providing forward -looking information or making forward -looking statements are considered reasonable by

management at the time, there can be no assurance that such assumptions will prove to be accurate in the future.

Forward-looking information and statements also involve known and unknown risks and uncertainties and other

factors, which may cause actual results, performances and achievements of NexGen to differ materially from any

projections of results, performances and achievements of NexGen expressed or implied by such forward -looking

information or statements, including, among others, the existence of negative operating cash flow and dependence

on third party financing, uncertainty of the availability of additional financing, the risk that pending assay results will

not confirm previously announced preliminary results, conclusions of economic valuations, the risk that actual

results of exploration activities will be different than anticipated, the cost of labour, eq uipment or materials will

increase more than expected, that the future price of uranium will decline or otherwise not rise to an economic

level, the appeal of alternate sources of energy to uranium -produced energy, that the Canadian dollar will

strengthen against the U.S. dollar, that mineral resources and reserves are not as estimated, that actual costs or

actual results of reclamation activities are greater than expected, that changes in project parameters and plans

continue to be refined and may result i n increased costs, of unexpected variations in mineral resources and

reserves, grade or recovery rates or other risks generally associated with mining, unanticipated delays in obtaining

governmental, regulatory or First Nations approvals, risks related to First Nations title and consultation, reliance

upon key management and other personnel, deficiencies in the Company's title to its properties, uninsurable risks,

failure to manage conflicts of interest, failure to obtain or maintain required permits and li cences, risks related to

changes in laws, regulations, policy and public perception, as well as those factors or other risks as more fully

described in NexGen's Annual Information Form dated March 3, 2026 filed with the securities commissions of all

of th e provinces of Canada except Quebec and in NexGen's 40 -F filed with the United States Securities and

Exchange Commission, which are available on SEDAR+ at www.sedarplus.ca and Edgar at www.sec.gov.

Although the Company has attempted to identify important factors that could cause actual results to differ

materially from those contained in the forward -looking information or statements or implied by forward -looking

information or statements, there may b e other factors that cause results not to be as anticipated, estimated or

intended. Readers are cautioned not to place undue reliance on forward -looking information or statements due

to the inherent uncertainty thereof.

There can be no assurance that forward -looking information and statements will prove to be accurate, as actual

results and future events could differ materially from those anticipated, estimated or intended. Accordingly, readers

should not place undue reli ance on forward -looking statements or information. The Company undertakes no

obligation to update or reissue forward -looking information as a result of new information or events except as

required by applicable securities laws.