Painkiller (also officially known as Pain Killer) is a band originally formed in 1991. Their style can be described as a mix of avant-garde jazz and grindcore; later albums also incorporated elements of ambient and dub.

The three primary members of the band were: John Zorn on saxophone, Bill Laswell on electric bass and Mick Harris (formerly of Napalm Death and founding member of Scorn) on drums. The band has also had several musicians make guest appearances both live and in the studio, including Yamatsuka Eye, Buckethead, Mike Patton, Makigami Koichi, Justin Broadrick and G. C. Green of Godflesh, and Keiji Haino of Fushitsusha.