Keir Dullea

Dr. David Bowman

Gary Lockwood

Dr. Frank Poole

William Sylvester

Dr. Heywood Floyd

Douglas Rain

HAL 9000 (voice)

Daniel Richter

Moonwatcher

Leonard Rossiter

Dr. Andrei Smyslov

Margaret Tyzack

Elena

Robert Beatty

Dr. Ralph Halvorsen

Sean Sullivan

Dr. Roy Michaels

Bill Weston

Astronaut