X-Men is a 2000 American superhero film directed by Bryan Singer from a screenplay by David Hayter and a story by Singer and Tom DeSanto, based on the Marvel Comics superhero team of the same name created by Stan Lee and Jack Kirby. Featuring an ensemble cast consisting of Patrick Stewart, Hugh Jackman, Ian McKellen, Halle Berry, Famke Janssen, James Marsden, Bruce Davison, Rebecca Romijn-Stamos, Ray Park, and Anna Paquin, the film depicts a world where an unknown proportion of people are mutants, possessing superhuman powers that make them distrusted by normal humans. It focuses on mutants Wolverine and Rogue as they are brought into a conflict between two groups with radically different approaches to bringing about the acceptance of mutant-kind: Charles Xavier's X-Men, and the Brotherhood of Mutants, led by Magneto.

Development of X-Men began as far back as 1984 with Orion Pictures, with James Cameron and Kathryn Bigelow in discussions at one point. 20th Century Fox bought the film rights in 1994, and various scripts and film treatments were commissioned from Andrew Kevin Walker, John Logan, Joss Whedon, and Michael Chabon. Singer signed to direct in 1996, with further rewrites by Ed Solomon, Singer, Tom DeSanto, Christopher McQuarrie, and Hayter, in which Beast and Nightcrawler were deleted over budget concerns from Fox. X-Men marked the American debut for Jackman, a last-second choice for Wolverine, cast three weeks into filming. Filming took place from September 22, 1999, to March 3, 2000, primarily in Toronto.

X-Men premiered at Ellis Island on July 12, 2000, and was released in the United States on July 14. The film received positive reviews from critics and was a box office success, grossing $296.3 million worldwide, becoming the ninth-highest-grossing film of 2000. Its success led to a series of films, with the first sequel, X2, released on May 2, 2003. Several actors reprise their roles in Marvel Cinematic Universe films, including Stewart in Doctor Strange in the Multiverse of Madness (2022), Jackman in Deadpool & Wolverine (2024), and Stewart, McKellen, Marsden, and Romijn in Avengers: Doomsday (2026).