Mark Margolis (born 1939 in Pennsylvania) is an American actor, who has been making movies since 1976.
Margolis is perhaps most famous for his supporting roles in Scarface and in three films by Darren Aronofsky: π, Requiem for a Dream, and The Fountain. Aronofsky wrote the role of Father Avila in The Fountain specifically for Margolis.
He has had recurring roles on numerous TV shows, including The Equalizer, HBO's Oz, and most recently NBC's Crossing Jordan. He also appeared in a first season episode of Quantum Leap.