X-Men: Days of Future Past is a 2014 superhero film based on the fictionalX-Men characters that appear in Marvel Comics. Directed by Bryan Singer, it is the seventh installment of the X-Men film series and acts as a sequel to both 2006's X-Men: The Last Stand and 2011's X-Men: First Class, featuring an ensemble cast with most of the actors from each movie. The screenplay, written by Simon Kinberg from a story conceived by him, and First Classwriters Matthew Vaughn and Jane Goldman, is inspired by the 1981 Uncanny X-Men storyline "Days of Future Past" produced by Chris Claremont and John Byrne. The plot has a time travel element focusing on two time periods: 2023, a dystopian future in which mutants are being exterminated by the robotSentinels; and 1973, to where Wolverine's mind is sent back into his younger self to prevent the incidents that lead to to the Sentinels' creation.

The film is a British-American co-production with a budget of US$200 million. Singer assumed as the director once First Class helmer Matthew Vaughn left, marking his return since 2003's X2. Principal photography began in Montreal, Quebec in April 2013 and concluded in August the same year, with additional filming and pick-ups taking place in November 2013 and February 2014. The film premiered in New York City on May 10, 2014, and was theatrically released on May 23.

X-Men: Days of Future Past received critical acclaim, becoming the best-reviewed film in the X-Men series. Reviewers commended its fresh visual style, story, and acting. It is also the highest-grossing film in the series, having earned over $746 million worldwide. A sequel, X-Men: Apocalypse, is scheduled for release on May 27, 2016, with Singer returning to direct.