"Rock On" is a song that was composed and sung by English singer/songwriter David Essex. In March of 1974, it was a Top 5 song (reaching the #5 position) on the U.S. Hot 100 pop-music chart. It was Essex's only BillboardTop 40 hit. The song also reached the #3 spot on the UK Singles Chart. "Rock On" was the title track to Essex's 1973 debut album and was also featured on the soundtrack album to the 1973 film That'll Be the Day, in which Essex had a starring role. The song can still frequently be heard on classic rock and oldies radio stations.

Essex later re-recorded the song in 1988 with updated lyrics. The version, which was remixed by Shep Pettibone, appeared on Essex's 1989 album Touching the Ghost.A single release of the updated version reached No. 93 on the U.K. charts.

The Essex recording was also featured in the movies Dick, The Devil's Rejectsand Sunset Strip,as well as on episodes of The Sopranosand Cold Case.

The song features a slow-tempo, soulful vocal delivery sung in a minor key, along with a minimalist, heavily-bass-driven instrumental accompaniment to Essex's vocals. The lyrics pay homage to early rock and roll and its surrounding youth subculture, and notably pay tribute to 1950s iconic rebel James Dean. The vocals are punctuated with distortion and echo effects to add to the soulful, hip, "power delivery" of Essex's lyrics. Still further adding to the song's emotion-laden, slightly-haunting feel is a heartbeat-sounding percussive hook at the beginning of the song, an atonal string glide in the middle of the song, a very brief duet with a very-soulful-sounding, deep-voiced backup singer towards the end of the song, and muffled-sounding, staccato percussive riffs interspersed throughout the song.

"Rock On" was covered by soap opera star and singer Michael Damian in 1989 and featured in the teen film, Dream a Little Dream,starring Corey Haim and Corey Feldman, among others.

Damian's version, which he also released from his independent album Where Do We Go From Hereon the Cypress Records label, which A&M Records distributed, was a harder-edged interpretation that employed none of the vocal or instrumental distortion Essex's version had used. It reached the #1 position on the BillboardHot 100 chart, thus outperforming Essex's original Billboard ranking. However, the song did get to #1 for Essex in '74 on the US Cashbox charts, the same week it was at #11 on the Billboard Charts.

This version was ranked #99 on VH1's 100 Greatest One Hit Wonders of the 80s.

The English hard-rock band Def Leppard covered the song on their 2006 album, Yeah!, which features cover versions of 1970s rock hits. It was released as the second single from the album.

The American alternative-rock group The Smashing Pumpkins included a live cover version of "Rock On", performed during their Sacred and Profanetour, on their 2001-release album Judas Ø, a bonus disc (containing B-sides and rarities) which accompanied the group's greatest hits album Rotten Apples.