"Collide" is a song performed by British recording artist Leona Lewis and Swedish DJ and record producer Avicii. It was written by Tim Bergling, Simon Jeffes, Arash Pournouri, Autumn Rowe, Sandy Wilhelm, with production helmed by Wilhelm under his production name Sandy Vee and Youngboyz. "Collide" is a house-inspired love song with instrumentation consisting of piano riffs and a guitar. The song was recorded for Lewis' third studio album Glassheart, but was not included on the album's final track listing.

Leona Louise Lewis is a British singer, songwriter, actress, and model. Born and raised in Islington, Inner London, she later attended the BRIT School for Performing Arts and Technology in Croydon. Lewis achieved national recognition when she won the third series of the television talent show The X Factor in 2006, winning a £1 million recording contract with Syco Music. Her winner's single, a cover of Kelly Clarkson's "A Moment Like This", peaked at number one for four weeks on the UK Singles Chart and broke a world record by reaching 50,000 digital downloads within 30 minutes. In February 2007, Lewis signed a five-album contract in the United States with Clive Davis's record label, J Records.