The son of orchestra conductor André Hossein, Paris-born Robert Hossein was trained at René Simon's acting school. Hossein labored away as actor/director with the legendary Theatre Grand Guignol in Montmartre, then spent several years on the "legitimate" stage. In films from 1955's Rififi (Du rififi chez les hommes (1955)), he has been generally cast as jaded villains. Making his movie directorial debut with The Wicked Go to Hell (1955) Les salauds vont en enfer (1955)), Hossein went on to call the shots on such Film Noir fare as Toi... le venin (1958) and J'ai tué Raspoutine (1967). In the 1960s, Robert Hossein appeared regularly as Jeoffrey de Peyrac in the soft-core Angélique films. He also worked as director.

As he was one of the most prominent leading men in French cinema, he was the screen partner of leading ladies like Brigitte Bardot, Michèle Mercier, Marina Vlady, Stéphane Audran, Claude Jade or the Italian beauty Sophia Loren, and more recently with Audrey Tautou in Vénus beauté (institut) (1999).