Walk Hard: The Dewey Cox Story is an upcoming comedy film expected to be released on December 21, 2007. The movie will star John C. Reilly as the fictional musician Dewey Cox and Jenna Fischer as his wife Darlene. The movie will be a parody of the biopic genre, especially the 2006 film Walk the Line. The film received an R rating from the MPAA for sexual content, graphic nudity, drug use, and language. The name is also a play on rock hard, which is evidenced by Dewey (COX).

The story of musician Dewey Cox (John C. Reilly), whose songs would change a nation. On his rock ‘n roll spiral, Cox sleeps with 411 women, marries 3 times, has 22 kids and 14 stepkids, stars in his own 70s TV show, collects friends ranging from Elvis to The Beatles to a chimp, and gets addicted to – and then kicks – every drug known to man… but despite it all, Cox grows into a national icon and eventually earns the love of a good woman – longtime backup singer Darlene (Jenna Fischer).

The tongue-in-cheek references in this fake biopic were drawn from a variety of sources. Apatow and Kasdan noted that they watched various types of biopics for inspiration including those of Jimi Hendrix and Marilyn Monroe.