Metallica: Some Kind of Monster is a 2004 American documentary film about American heavy metal band Metallica. The film follows the band from 2001 to 2003, a turbulent period in the band's history which included the production of their 2003 album St. Anger, frontman James Hetfield entering into rehab for alcoholism and the departure of bassist Jason Newsted as well as the hiring of his replacement Robert Trujillo. The title of the film shares its name with the song of the same name from St. Anger.

Metallica is an American heavy metal band. The band was formed in 1981 in Los Angeles by vocalist and guitarist James Hetfield and drummer Lars Ulrich, and has been based in San Francisco for most of its career. The band's fast tempos, instrumentals and aggressive musicianship made them one of the founding "big four" bands of thrash metal, alongside Megadeth, Anthrax and Slayer. Metallica's current lineup comprises founding members and primary songwriters Hetfield and Ulrich, longtime lead guitarist Kirk Hammett and bassist Robert Trujillo. Guitarist Dave Mustaine, who formed Megadeth after being fired from Metallica, and bassists Ron McGovney, Cliff Burton and Jason Newsted are former members of the band.