Bennett was born in York, Western Australia. Her sisters Enid (1893-1969) and Catherine (1901–1978) were also Hollywood film actresses. Bennett began acting in films in 1917 and later made the transition to talking pictures with bit roles in Monsieur Verdoux (1947), Abbott and Costello Meet the Killer, Boris Karloff (1949), and Washington Story (1952). In 1952, she appeared as Charlie Chaplin's landlady in the film Limelight and later had guest roles on The Great Gildersleeve, Four Star Playhouse, Sergeant Preston of the Yukon, I Love Lucy, Schlitz Playhouse of Stars, and December Bride. From 1959 to 1961, she had a recurring role on The Many Loves of Dobie Gillis.