Walk the Line is a 2005 American biographical drama film directed by James Mangold. The screenplay, written by Mangold and Gill Dennis, is based on two autobiographies by the American singer-songwriter Johnny Cash: Man in Black: His Own Story in His Own Words (1975) and Cash: The Autobiography (1997). The film follows Cash's early life, his romance with the singer June Carter, his ascent in the country music scene, and his drug addiction. It stars Joaquin Phoenix as Cash, Reese Witherspoon as Carter, Ginnifer Goodwin as Cash's first wife Vivian Liberto, and Robert Patrick as Cash's father.

Walk the Line premiered at the Telluride Film Festival on September 4, 2005, and was theatrically released by 20th Century Fox on November 18. It received positive reviews and was a box office success, grossing $187 million on a $28 million budget. At the 78th Academy Awards, Witherspoon won Best Actress while the film was also nominated for Best Actor (Phoenix), Best Sound, Best Costume Design, and Best Film Editing.