Denison Announces Filing of Annual Report on Form 40-F

Press Release

TORONTO, March 29, 2021- Denison Mines Corp. (“Denison” or the “Company”) (TSX: DML) (NYSE American: DNN) is pleased to announce that it has filed its 2020 annual report on Form 40-F with the U.S. Securities and Exchange Commission (“SEC”). Denison’s Form 40-F includes its management discussion and analysis and audited financial statements for the year ended December 31, 2020. The Form 40-F is available on Denison’s website at www.denisonmines.com, and on the SEC’s website at www.sec.gov/edgar.shtml. View PDF Version.

Denison’s Annual Information Form has also been filed with Canadian regulatory authorities and is available on Denison’s website at www.denisonmines.com and under the Company’s profile on SEDAR at www.sedar.com.

Holders of Denison’s securities may receive a free printed copy of the Company’s most recent Form 40-F and Annual Report, including the audited financial statements, by sending an email request to info@denisonmines.com, by submitting a request online at www.denisonmines.com, or by writing to Denison Mines Corp., 1100 – 40 University Avenue, Toronto, Ontario, Canada M5J 1T1.

David Cates, President and Chief Executive Officer, (416) 979-1991 ext. 362; Sophia Shane, Investor Relations, (604) 689-7842

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