Mayo Joseph Thompson Jr. (born February 26, 1944) is an American musician and visual artist best known as the leader of the experimental rock band Red Krayola. He released his only solo album Corky's Debt to His Father in 1970, and later collaborated with the English conceptual art collective Art & Language. He formed the band Saddlesore with Rick Barthelme, Frank Davis and Cassell Webb in 1971, and the Rockin' Blue Diamonds in 1972 with Barthelme, Rock Romano and Tucker Bradley. He later worked with Greek composer Manos Hatzidakis and artist Robert Rauschenberg.

By the late 1970s, he moved to England and began working with Rough Trade where he co-produced releases with Geoff Travis for groups such as the Monochrome Set, Stiff Little Fingers, the Raincoats, the Fall, Scritti Politti, Blue Orchids, LiLiPUT and Cabaret Voltaire. Thompson briefly joined the band Pere Ubu and was credited as an associate producer for the Smiths' "The Queen Is Dead" music video. He contributed to film soundtracks for Lizzie Borden's Born in Flames and Derek Jarman's The Last of England. He later produced the Chills, Felt, Shop Assistants and Primal Scream in the mid-to late 1980s. Thompson would move to Germany and collaborate with artists and musicians such as Albert Oehlen, Dieter Moebius and Conny Plank.

During the 1990s, Thompson moved back to the United States, signed to the label Drag City and briefly joined the German free improvisation group COWWS Quintet. In 1994, he taught at the Art Center College of Design in Pasadena until 2008. His paintings and visual artwork were later exhibited at Galerie Buchholz. He released two novels Art & Mystery (2018) and After Math: Art, Mystery - Part II (2023).

Mayo Joseph Thompson Jr. was born on February 26, 1944, at St. Joseph Medical Center in Houston, Texas, to father Mayo Joseph Thomson Sr. and mother Hazel Margaret Muhl. Shortly after he was born, his parents divorced. Thompson grew up alone with his mother in Houston, who became a teacher at San Jacinto High School. His father, Mayo Thompson Sr. had previously been in the armed services, and later became a lawyer and member of the Federal Trade Commission.

Thompson's formal education includes Garden of Arts Kindergarten until Holy Rosary Elementary School through fifth grade, then Moye Military School until high school at Cascia Hall College Preparatory School, from which he received a diploma in 1962. He went on to study at the University of St. Thomas, where he tried variously, off and on, pre-Law, Creative Writing, English and American Literature, Philosophy, and Art History, before dropping out.

In 1955, Mayo Thompson began taking piano lessons at the age of 11, where he first became interested in composing music. In 1958, he jammed once in the music building of Moye Military School on piano with a friend who played trumpet and drums. Thompson went on to study at the University of St. Thomas, where he found an "affinity for jazz". In 1963, he met Frederick Barthelme (brother of novelist Donald Barthelme). On November 15, 1964, Thompson performed a cover of "Baby, Please Don't Go" at the University of St. Thomas. At the time, Thompson was a part of a folk music parody band known as the Seventy-Three Balalaikas, which consisted of Sam Irwin of the Sixpence, Bob Raines and Paul Norris.

In 1965, Thompson embarked on a school trip to Europe. On returning, he was inspired by Beatlemania to start a rock band. He later stated he was "more interested in creating new material than interpreting old material". In mid-1966, amid the burgeoning Houston psychedelic scene, Thompson formed the band Red Crayola with Rick Barthelme and Steve Cunningham, they signed to International Artists after being discovered by producer Lelan Rogers performing for radio station KNUZ's Battle of the Bands event at the Gulfgate Mall. They became labelmates with the 13th Floor Elevators, with Roky Erickson performing on their debut album.

In late 1967, Rick Barthelme left the Red Crayola, leading to Thompson briefly working as a sound man for Joseph Byrd and his band the United States of America in Los Angeles. In March 1968, Thompson began working with local musician Johndavid Bartlett at Gold Star Studios, the same place where "She's About a Mover" was recorded. Bartlett had joined in on rehearsals during the Red Crayola's early days and would sometimes get the opportunity to play his own original songs. Because of this, Thompson took an affinity for his songwriting and got him signed to the International Artists record label. He started producing the album which contained instrumental cameos from Johnny Winter, Jimmy Reed and Stacy Sutherland of the 13th Floor Elevators. The album was to be called Mother's Milk; however, by the time it was supposed to be released, the label folded and the tapes were lost.