He is expected to be sidelined four to six weeks.
Team physician Dr. Richard D. Parker performed the surgery to repair a torn lateral meniscus. Diop suffered the injury in the first overtime of Saturday's 122-115 double-overtime loss to Memphis.
Diop is averaging 2.8 points and 4.5 rebounds in 16 games. The 7-foot, 300-pounder was selected by the Cavaliers with the eighth overall pick in the 2001 draft and has averaged 1.7 points and 2.7 boards in 114 games.
Cleveland (4-15), which has lost eight straight games, hosts the Atlanta Hawks on Saturday.