Denison Mines Corp. is a Canadian uranium exploration, development, and production company. Founded by Stephen B. Roman, and best known for its uranium mining in Blind River and Elliot Lake, it later diversified into coal, potash, and other projects.

Currently, Denison's principal assets are its northern Saskatchewan interests in the McClean Lake mine and the Midwest Uranium Project. Denison serves as manager for Uranium Participation Corporation, a Toronto-based investment fund which holds no licence to deal in uranium. Denison recently purchased a number of projects from Fission Energy Corp - a uranium exploration company founded by Dev Randhawa. The purchase, which included Fission's uranium deposit at Waterbury Lake Canada's Athabasca Basin, means Denison is quite possibly the leading uranium exploration company in the Basin. Denison Mines also acquired the Fission Energy name and a new company, Fission Uranium Corp. was spun out by the Fission Energy management team.

15% of the company is owned by Korea Electric Power Corporation (KEPCO).

In January 2017 Denison announced it had executed an agreement to increase ownership of the Wheeler River Uranium Project in the Athabasca Basin to 66%.