James Edward Rowser (born April 18, 1926 - Philadelphia, Pennsylvania; died June 24, 2004 - Teaneck, New Jersey) was an American jazz double-bassist.
Rowser learned to play piano as a youth in addition to bass. He played with the house band at Philadelphia's Blue Note club, accompanying touring musicians such as Cannonball Adderley, Miles Davis, Billie Holiday, J.J. Johnson, Anita O'Day, Charlie Parker, and Kai Winding. In the late 1950s he played with Dinah Washington, Maynard Ferguson, Lee Morgan, and Red Garland. He was active in New York in the early 1960s with Junior Mance, Ray Bryant, Herb Ellis, and Illinois Jacquet, and toured internationally with Benny Goodman and Friedrich Gulda in 1963-1964. Later in the 1960s he worked with Al Cohn and Zoot Sims and then with Les McCann; he remained with McCann well into the 1970s. In the 1980s he played with Bryant once more and also with Hilton Ruiz. He returned to school in the 1980s, receiving a bachelor's and master's from Lehman College, and then taught music in New Jersey in the 1990s.