Born Joy Cerrette Paige , she was the daughter of Mexican-American silent film star Don Alvarado (born José Paige) and Ann Boyar (1908-1990), the daughter of Russian Jewish immigrants. Her parents divorced when she was five.
In 1936, her mother married Jack Warner, then head of Warner Brothers studios. Warner, however, did not encourage his stepdaughter's interest in acting. Joy, who initially thought the script to Casablanca was "old fashioned" and "cliched", landed the role on her own and Warner reluctantly approved. She was only seventeen and fresh out of high school.
Warner, however, refused to sign Page to a contract, and she never featured in another Warner Brothers film. She went on to perform in a number of films for other studios and made some television appearances. Page married actor William T. Orr and he became a Warner Bros. executive, leading to accusations of nepotism. She retired from acting after appearing in the first season of the Disney series The Swamp Fox in 1959.
She and Orr divorced in 1970, and their son, Gregory Orr, is a writer and producer.
Page died on April 18, 2008, of complications arising from a stroke and pneumonia.