Cinderella Man is a 2005 American biographical drama film directed by Ron Howard. The film stars Russell Crowe, Renée Zellweger and Paul Giamatti. It tells the true story of heavyweight boxing champion James J. Braddock, who was dubbed "The Cinderella Man" by journalist Damon Runyon. The film marked the second collaboration for Howard and Crowe, succeeding A Beautiful Mind (2001).

Universal Pictures and Miramax Films released Cinderella Man in the United States on June 3, 2005. It received generally positive reviews from critics and grossed $108 million worldwide.

Cinderella Man received three Academy Award nominations, including Best Supporting Actor for Giamatti. Crowe and Giamatti both received Golden Globe Award and Screen Actors Guild Award nominations for their performances, and Giamatti won the latter alongside a Critics' Choice Movie Award for Best Supporting Actor. Retrospective critical reviews have named Cinderella Man as one of the greatest boxing films of all time.

James J. Braddock is an Irish-American boxer from New Jersey, formerly a light heavyweight contender, who is forced to give up boxing after breaking his hand in the ring. This is both a relief and a burden to his wife, Mae. She cannot bring herself to watch the violence of his chosen profession, yet she knows they will not have enough income without his boxing.

As the United States enters the Great Depression, Braddock does manual labor as a longshoreman to support his family, even with his injured hand. However, he cannot get work every day. Thanks to a last-minute cancellation by another boxer, Braddock's longtime manager and friend, Joe Gould, offers him a chance to fill in for just one night and earn cash. The fight is against the number-two contender in the world, Corn Griffin.

Braddock stuns the boxing experts and fans with a third-round knockout of his formidable opponent. He believes that while his right hand was broken, he became more proficient with his left hand, improving his in-ring ability. Despite Mae's objections, Braddock takes up Gould's offer to return to the ring. Mae resents this attempt by Gould to profit from her husband's dangerous livelihood, until she discovers that Gould and his wife also have been devastated by hard times.

With a shot at the heavyweight championship held by Max Baer a possibility, Braddock continues to win. Out of a sense of pride, he uses a portion of his prize money to pay back money to the government given to him while unemployed. When his rags to riches story gets out, the sportswriter Damon Runyon dubs him "The Cinderella Man", and before long Braddock comes to represent the hopes and aspirations of the American public struggling with the Depression.

After wins against John Henry Lewis and Art Lasky, a title fight against Baer comes his way. Braddock is a 10-to-1 underdog. Baer is so destructive that the fight's promoter, James Johnston, forces both Braddock and Gould to watch a film of Baer in action, just so he can maintain later that he warned them what Braddock was up against, as Baer had reportedly killed two men in the ring, Frankie Campbell and Ernie Schaaf.