Kill 'Em All is the debut studio album by the American heavy metal band Metallica, released on July 25, 1983, through the independent label Megaforce Records. After forming in 1981, Metallica began by playing shows in local clubs in Los Angeles. They recorded several demos to gain attention from club owners and eventually relocated to San Francisco to secure the services of bassist Cliff Burton. The group's No Life 'til Leather demo tape (1982) was noticed by Megaforce label head Jon Zazula, who signed them and provided a budget of $15,000 for recording. The album was recorded in May with producer Paul Curcio at the Music America Studios in Rochester, New York. It was originally intended to be titled Metal Up Your Ass, with cover art featuring a hand clutching a dagger emerging from a toilet bowl. Zazula convinced the band to change the name because distributors feared that releasing an album with such an offensive title and artwork would diminish its chances of commercial success.

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.