"Start!" is the eleventh UK single release by punk rock band, The Jam and their second number-one, following "Going Underground"/"Dreams of Children". Upon its release on 15 August 1980, it debuted at number three, and two weeks later reached number one for one week. Written by Paul Weller and produced by Vic Coppersmith-Heaven and The Jam, "Start!" was the lead single from the band's fifth album Sound Affects. The single's B-side is "Liza Radley".

"Start!" is based on both the main guitar riff and bass riff of The Beatles' 1966 song "Taxman" from the album Revolver, written by George Harrison. Likewise, The Jam's "Dreams of Children" had featured the same "Taxman" bassline, played then as a lead guitar riff.

The album version of the song runs at 2:30 and features trumpets in the final section. The single version, also featured on the "Snap!" compilation, is edited and slightly remixed, and omits the trumpets.

Beastie Boys covered the song on their "Alive" single.