Marcus Miller (born William Henry Marcus Miller Jr.; June 14, 1959) is an American jazz composer, producer and multi-instrumentalist, best known as a bass guitarist. He has worked with trumpeter Miles Davis, pianist Herbie Hancock, singer Luther Vandross, and saxophonist David Sanborn, among others.

Miller was born in Brooklyn, New York City, in 1959 and raised in a musical family that includes his father, William Miller (a church organist and choir director) and jazz pianist Wynton Kelly. He is classically trained as a clarinetist and also plays keyboards, saxophone and guitar. He began to work regularly in New York City, eventually playing bass and writing music for jazz flutist Bobbi Humphrey and keyboardist Lonnie Liston Smith. Miller soon became a session musician, appearing on over 500 albums by such artists as Michael Jackson, Herbie Hancock, Mariah Carey, Wayne Shorter, McCoy Tyner, Frank Sinatra, George Benson, Dr. John, Aretha Franklin, Elton John, Joe Walsh, Grover Washington Jr., Donald Fagen, Bill Withers, Kazumi Watanabe, Chaka Khan, LL Cool J and Flavio Sala.