"Greatest Day" is a song by British pop group Take That. It was released through Polydor Records on 24 November 2008 as the lead single from their fifth studio album, The Circus (2008). The song was written by the band and produced by John Shanks. The song reached number one on the UK Singles Chart, becoming the band's eleventh UK number-one single. It has since been certified Platinum in the United Kingdom selling over 600,000 copies.