Benjamin Alexander Riley Jr. (July 17, 1933 – November 18, 2017) was an American jazz drummer known for his work with Thelonious Monk, as well as Alice Coltrane, Stan Getz, Eddie “Lockjaw” Davis, Ahmad Jamal, and as a member of the group Sphere. During the 1970s and 1980s he was a member of the New York Jazz Quartet.

Benjamin Alexander Riley Jr. was born in Savannah, Georgia, on July 17, 1933, and at the age of four moved with his family to New York City.

Riley performed with Randy Weston, Sonny Stitt, Stan Getz, Junior Mance, Kenny Burrell, Eddie “Lockjaw” Davis–Johnny Griffin (1960–1962), Ahmad Jamal, Billy Taylor, and Ray Bryant. He then spent 1964 to 1967 in Thelonious Monk‘s quartet. After Monk, he played with Alice Coltrane (intermittently between 1968 and 1975), Ron Carter(1975–1977), Jim Hall (1981), and the bands the New York Jazz Quartet (1970s and 1980s) and Sphere. He also played frequently with pianist Abdullah Ibrahim.

Riley died of lung disease and complications of diabetes in West Islip, New York on November 18, 2017, aged 84.