Mark Clarke is an English musician, bass player and singer, best known for his work with Colosseum and Mountain, as well as brief stints with Uriah Heep and Rainbow.

Colosseum are an English jazz rock band, mixing blues, rock and jazz-based improvisation. Colin Larkin wrote that "the commercial acceptance of jazz rock in the UK" was mainly due to the band. Between 1975 and 1978 a separate band Colosseum II existed playing progressive rock.