Slayer is an American thrash metal band, founded in Huntington Park, California in 1981 by Tom Araya (bass guitar, vocals), Kerry King (guitars), Jeff Hanneman (guitars) and Dave Lombardo (drums). Lombardo had left the band to explore varied drumming styles, notably his work in Mike Patton's Fantômas. He was replaced by Paul Bostaph, but has now returned to the drum stool. Hanneman and King are the group's main songwriters.

Slayer (along with Metallica, Anthrax, Megadeth and others) are often credited with creating American thrash metal by speeding up the sound of New Wave of British Heavy Metal bands like Iron Maiden, Judas Priest and Venom. Slayer were also great fans of hardcore punk, influenced by the likes of Minor Threat, Dead Kennedys and Misfits, and borrowed some of that music's emphasis on extremely fast tempos in many of their songs.

Though Araya has never used the low "grunt" vocal style usually associated with death metal, Slayer's music (most notably on the albums Slayer - Hell Awaits (1985) and Slayer - Reign in Blood (1986)) are generally regarded as having exerted a major influence on death metal and black metal. Moreover, Reign in Blood was the first of many albums to be produced by well-known and respected Def Jam Co-Founder, Rick Rubin.