Parents - Oscar Marin, a policeman, and Elsa Melsa, a secretary. Marin graduated from California State University Northridge.

Although his parents were highly cultured people, Cheech remained a street Hispanic teenager.

As a child, Cheech Marin created a musical group, gathering it from classmates. Composing songs, Cheech became interested in poetry even more than music. Then the poems became parodic, they began to turn into prose, puns, and sketches. In the 1960s, as an opponent of the Vietnam War, Marin travels to Vancouver, where he meets Tommy Chong. In 1968, the comic duo Cheech and Chong was born. He started with five-minute performances at a club owned by Chong. A few years later, Cheech and Chong were already the opening team during the American tour of The Rolling Stones. And in 1972 they won a Grammy for Best Musical Comedy Album. In 1984, the duo broke up.

In the 1970s, he married, and together with his wife adopted a girl from an orphanage.

Also, in 1998, he participated in the recording of the Follow the Leader album by KoRn.