Marcus Shelby (born February 2, 1966, in Anchorage, Alaska) is an American bass player, composer and educator best known for his major works for jazz orchestra, Port Chicago, Harriet Tubman, Soul of the Movement: Meditations on Dr. Martin Luther King Jr., and Beyond the Blues: A Prison Oratorio. He has led the Marcus Shelby Jazz Orchestra since 2001 and has recorded with artists as diverse as Ledisi and Tom Waits.

He has contributed numerous musical compositions to works created in collaboration with dance ensembles and theater artists ranging from California Shakespeare Theater to Intersection for the Arts.