"Clocks" emerged in conception during the late stages into the production of Coldplay's second album, A Rush of Blood to the Head. The band's vocalist, Chris Martin, came in studio late one night. A riff popped up in Martin's mind and wrote it on the piano. Martin presented the riff to the band's guitarist, Jonny Buckland, who then added guitar chords on the basic track.
During the writing of "Clocks", the band had already made 10 songs for the album. .