X is a noted punk rock band, formed in Los Angeles in 1977. While they achieved only limited mainstream success, they were widely considered one of the most accessible and tuneful of Los Angeles' many punk bands. Their landmark 1980 record Los Angeles resonated so loudly with the artisans of the city it is named after, that the band received an Official Certificate of Recognition from the City of Los Angeles in acknowledgment of their important contributions to Los Angeles music and culture.

Original members were Exene Cervenka (vocals), John Doe (bass and vocals), Billy Zoom (guitar) and DJ Bonebrake (drums). After Zoom retired from the band, Tony Gilkyson replaced him on guitar. Zoom reunited with X in 1998. The original line-up now tours sporadically and still has a sizable and vociferous fanbase.

Their albums had a hard-driving sound that occasionally flirted with country and blues; one critic suggests that X "were not just one of the greatest punk bands, but one of the greatest live rock acts of all time."