"You're My Number One" is a song by British pop group S Club 7, released as the fourth and final single from the band's debut album, S Club (1999), on 13 December 1999. The single was released only in UK as a double A-side with "Two in a Million" and peaked at number two on the UK Singles Chart; in other countries, only "Two in a Million" was released. It was the first S Club 7 single to be released as a double A-side, later followed by "Say Goodbye" and "Love Ain't Gonna Wait for You" in 2003. "You're My Number One" is described as a fun up-tempo retro number.