Walk Hard: The Dewey Cox Story is a 2007 American musical comedy film directed by Jake Kasdan, and written by Kasdan and co-producer Judd Apatow. It stars John C. Reilly, Kristen Wiig, Tim Meadows and Jenna Fischer. A parody of the biopic genre, Walk Hard is the story of a fictional early rock and roll star played by Reilly.

Walk Hard primarily references the musical biopics Ray (2004) and Walk the Line (2005); in addition to Ray Charles and Johnny Cash, the "Dewey Cox" character includes elements of the lives and careers of other notable musicians including Roy Orbison, Glen Campbell, Bob Dylan, Jerry Lee Lewis, Donovan, John Lennon, James Brown, Jim Morrison, Conway Twitty, Neil Diamond, Hank Williams, and Brian Wilson. The film portrays fictional versions of artists Buddy Holly, the Big Bopper, Elvis Presley, and the Beatles; some artists appear as themselves, including Eddie Vedder, Jewel and Ghostface Killah. In addition, the film parodies or pays tribute to the musical styles of David Bowie, Billy Joel, Van Dyke Parks, the Gun Club, and seventies punk rock.

The film was released in North America on December 21, 2007. It received positive reviews from critics but was a box office disappointment, grossing only $20 million against a $35 million budget. The film has since become a cult classic.