X is an Australian punk rock band, formed in Sydney in 1977 founded by the late Ian Rilen Steve Lucas, Ian Krahe and Steve Cafiero. The band has split and reformed several times. Most noted non-original member was Cathy Green (drums).

Their first album X-Aspirations (1979) redefined the Australian underground music scene. Their followup album At Home With You (1985) stayed in the top 20 Independent charts for 29 months. Both albums were produced by Lobby Loyde.