Samuel Alexander "Sam" O'Steen (November 6, 1923 – October 11, 2000) was an American film editor and director. He had an extended, notable collaboration with the director Mike Nichols, with whom he edited twelve films between 1966 and 1994. Among the notable films that O'Steen edited were Who's Afraid of Virginia Woolf (directed by Mike Nichols, 1966), Cool Hand Luke (directed by Stuart Rosenberg, 1967), The Graduate (directed by Mike Nichols, 1967), Rosemary's Baby (directed by Roman Polanski, 1968), and Chinatown (directed by Roman Polanski, 1974).