Sum 41 is a Canadian rock band from Ajax, Ontario. The band was formed in 1996 and currently consists of members Deryck Whibley (lead vocals, rhythm guitar), Tom Thacker (lead guitar, backing vocals), Jason McCaslin (bass guitar, backing vocals) and Steve Jocz (drums).

In 1999, the band signed an international record deal with Island Records. The band released their debut album, All Killer, No Filler in 2001. The band achieved mainstream success with their first single from the album, "Fat Lip", which reached number-one on the Billboard Modern Rock Tracks chart and remains the band's most successful single to date. All Killer No Filler' was certified platinum in the United States, Canada and in the UK. The band has since released four more studio albums: Does This Look Infected? (2002), Chuck (2004) Underclass Hero (2007) and Screaming Bloody Murder (2011).

The band often performs more than 300 times each year and holds long global tours, most of which last more than a year. They have been nominated for seven Juno Awards and have won twice (Group of the Year in 2002 and Rock Album of the Year for Chuck in 2005). Sum 41 was nominated for a Grammy Award for Best Hard Rock/Metal Performance for the song Blood In My Eyes, however they lost to the Foo Fighters.[