Michael Clarke Duncan (born December 10, 1957) is an American actor, best known for his breakout role as John Coffey in The Green Mile, for which he was nominated for an Academy Award and a Golden Globe.

Duncan was born in Chicago, Illinois and grew up in a single-parent household with his sister, Judy, and mother, Jean Duncan (a house cleaner), after his father left. He always wanted to act, but had to drop out of the Communications program at Alcorn State University to support his family when his mother became ill. Duncan's large frame — 6 feet 5 inches and 315 lbs — helped him in his jobs digging ditches for the People's Gas Company and being a bouncer at different Chicago clubs. On September 24, 2008, he appeared on Late Late Show with Craig Ferguson. During his interview with Ferguson, Duncan admitted that one of his many jobs had been a stripper "back in the day" and his stage name was Black Caesar.

In 1979, he participated in the Disco Demolition Night at Comiskey Park, home of the Chicago White Sox: he was among the first 100 people to run onto the field and he slid into third base. He also had a silver belt buckle stolen during the ensuing riot and apparently stole one of Bill Melton's bats from the dugout.