Sum 41 is a Canadian rock band from Ajax, Ontario, Canada. The band was formed in 1996 and as of 2014 consists of members Deryck Whibley (lead vocals, rhythm guitar), Tom Thacker (lead guitar, backing vocals), and Jason McCaslin (bass guitar, backing vocals). In April 2013, former drummer Steve Jocz announced his departure from the band.

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 United Kingdom.