Keith Morris (born September 18, 1955) is an American singer and songwriter known for his role as frontman of the hardcore punk bands Black Flag, Circle Jerks, and Off!. Born and raised in Hermosa Beach, California, he formed Black Flag at the age of 21 with guitarist Greg Ginn and performed on the band's 1979 debut EP Nervous Breakdown. Shortly after leaving Black Flag in 1979, he formed the Circle Jerks with guitarist Greg Hetson; the band released seven albums between 1980 and 1995 and have broken up and reformed on numerous occasions. In 2009 Morris formed the supergroup Off! with guitarist Dimitri Coats, bassist Steven Shane McDonald, and drummer Mario Rubalcaba. Morris has also appeared as a guest vocalist on several albums by other artists.

In 1976, Morris co-founded Black Flag (then-known as Panic) along with guitarist Greg Ginn. Their work ethic proved too challenging for some early members; Ginn and Morris had an especially hard time finding a reliable bass guitarist, and often rehearsed without a bassist, a factor that contributed to the development of Ginn's distinctive, often low-pitched guitar sound. The band went through three bass players before Chuck Dukowski joined and then Robo answered a Pennysaver ad and became their drummer.

After a number of line-up changes, Morris recorded vocals for the first Black Flag EP Nervous Breakdown. After two years in the band, Morris left the band citing, among other reasons, creative differences with Ginn and Dukowski and his own "freaking out on cocaine and speed." Morris stated in his autobiography he had also become disillusioned with what he saw as Black Flag's "militaristic" approach to practicing, despite not getting many shows at the time, and being left "out of the loop" on decisions for the band

After leaving Black Flag in 1979, Morris founded the Circle Jerks, along with former Redd Kross guitarist Greg Hetson. They were soon joined by Roger Rogerson (bass) and Lucky Lehrer (drums). In contrast to the top-down decision-making of Black Flag, the Circle Jerks agreed on collective decisions for material and performances. Morris and the band increased their global popularity after being featured in the Penelope Spheeris 1981 documentary The Decline of Western Civilization. Cited as one of the most important hardcore punk groups, the Circle Jerks were active until 1990, when Hetson left the band to continue playing guitar and release a number of albums with Bad Religion.