William Jones Jr. (October 20, 1929 – April 1991) was a jazz drummer.^[1] He is known for playing and recording with Thelonious Monk, Lester Young, Elmo Hope, and Charles Mingus.^[1]

Jones was born in New York on October 20, 1929.^[1] He mainly taught himself to play the drums,^[1] and played left handed.^[2]: 164 He played and recorded with pianist Thelonious Monk in 1953,^[1] including on the album Thelonious Monk and Sonny Rollins. This recording, on November 13, was Jones' first.^[2] He also appeared with Monk on the television program The Tonight Show, on June 10, 1955.^[2]: 187 Jones was sideman for another pianist's recording in 1955 – Elmo Hope's Meditations;^[3]: 723 and for Randy Weston's The Modern Art of Jazz by Randy Weston in the following year.^[3]: 1491 In 1956 Jones had a two-week engagement with Monk in Philadelphia.^[2]: 212 Jones also played with Kenny Dorham, J. J. Johnson, Charlie Parker, and Cecil Payne in the mid-1950s.^[1]

In 1955–56 Jones was part of Charles Mingus' Jazz Workshop,^[1] and was the drummer in the bassist's band that recorded Pithecanthropus Erectus, which helped develop a freer form of group improvisation.^[3]: 1001 Jones was tenor saxophonist Lester Young's drummer from late 1956 to early 1959.^[1] In 1961, Jones played on Sun Ra's The Futuristic Sounds of Sun Ra.^[1][4] After this, nothing is known about Jones, and his date of death was taken from social security records.^[1] These associations – with the traditional Young and the avant-garde Sun Ra – illustrated Jones' versatility.^[5]