"Speed of Sound" is a song by British rock band Coldplay. It was written by all members of the band for their third studio album, X&Y (2005). Constructed around a piano and guitar riff, the song builds into a huge, synthesiser-heavy chorus. It was released by Parlophone Records as the lead single from the album. "Speed of Sound" made its radio premiere on BBC Radio 1 with Lamacq on 19 April, then was serviced to US radio on 18 April 2005. The song was released physically in Japan on 11 May with two B-sides: "Things I Don't Understand" and "Proof". In the United Kingdom, the single was issued on 23 May 2005.

Coldplay are a British rock band formed in London in 1997, consisting of vocalist and pianist Chris Martin, lead guitarist Jonny Buckland, bassist Guy Berryman, drummer and percussionist Will Champion, and manager Phil Harvey. They are best known for their live performances, having also impacted popular culture with their artistry, advocacy and achievements.