Clarence Williams III (born August 21, 1939) is an American actor.

His first major acting role was as Lincoln Hayes on Aaron Spelling's TV series The Mod Squad. He has guest-starred in television shows such as Hill Street Blues, Miami Vice, The Highwayman, Twin Peaks, Star Trek: Deep Space Nine, Burn Notice, Everybody Hates Chris, and in a recurring role as Philby Cross in the Mystery Woman movie series on the Hallmark Channel. He has appeared in feature films such as The Cool World, Deep Cover, Tales from the Hood, Half-Baked, Hoodlum, I'm Gonna Get You Sucka, The Legend of 1900, and Purple Rain. He also played a supportive role as George Wallace's fictional African-American butler and caretaker in the 1997 TNT TV Movie George Wallace

Williams was born in New York City. His grandfather was Clarence Williams, the jazz pianist and composer. He was raised by his grandmother. Williams was married to African-American actress Gloria Foster until her death on September 29, 2001. One of Williams's closest friends is actor Eric Braeden.