The Hangover is a 2009 American comedy film directed by Todd Phillips, written by Jon Lucas and Scott Moore, and produced by Todd Phillips and Daniel Goldberg. The film was produced by Legendary Pictures for Warner Bros. Pictures. It stars Bradley Cooper, Ed Helms, Zach Galifianakis, Justin Bartha, Mike Tyson and Heather Graham.

The plot follows four friends who travel to Las Vegas for a bachelor party, only to wake up the next morning not remembering a thing and missing the groom, whose wedding is scheduled to occur the next day. The film was inspired by the filmmakers' real-life misadventures, and was released in North America on June 5, 2009, to critical praise and box office success, and going on to win awards including the Golden Globe Award for Best Motion Picture – Musical or Comedy.