Bob Stewart (born February 3, 1945, in Sioux Falls, South Dakota), is an American jazz tuba player. He received his Bachelor of Music Education degree from the Philadelphia College of the Performing Arts and his master's degree in education from Lehman College Graduate School. Stewart taught music in Pennsylvania public schools and at the Fiorello H. LaGuardia High School of Music & Art and Performing Arts in New York City. He is now a professor at the Juilliard School and is a "distinguished lecturer" at Lehman College.
Stewart has toured and recorded with such artists as Charles Mingus, Gil Evans, Carla Bley, Muhal Richard Abrams, David Murray, Taj Mahal, Dizzy Gillespie, McCoy Tyner, Freddie Hubbard, Don Cherry, Nicholas Payton, Wynton Marsalis, Charlie Haden, Lester Bowie, Bill Frisell and many others in the United States, Europe, and Eastern Asia.
He was a frequent collaborator with saxophonist Arthur Blythe from the 1970s into the early 2000s, often taking the place of the string bass that traditionally supports a jazz ensemble. In their review of Blythe's album Lenox Avenue Breakdown, the editors of The Penguin Guide to Jazz called Stewart's title track solo "one of the few genuinely important tuba statements in jazz."