British actor known for his portrayals of villianous characters such as Count Teck de Brancovis in both the stage (1941) and screen (1943) versions of Lillian Hellman's Watch on the Rhine.

Coulouris studied at the Central School of Speech and Drama in London; he made his stage debut there in 1926 and his Broadway debut three years later. He drew critical acclaim for his performance as Yank in the 1928 Cambridge Festival Theatre production of Eugene O'Neill's The Hairy Ape. As an original member of Orson Welles's Mercury Theatre, Coulouris played Marc Antony in that company's staging of Julius Caesar (1937). After appearing with Welles in the film Citizen Kane (1941), Coulouris moved easily between motion pictures and the theatre on both sides of the Atlantic Ocean. His notable films include None but the Lonely Heart (1944), An Outcast of the Islands (1951), I Accuse (1958), Mahler (1974), and The Long Good Friday (1980).