Born in St. Petersburg, West Virginia, Banks attended a school of Russian ballet as a little girl and excelled in swimming as a high school student. Her acting talent earned her a scholarship to the American Academy of Dramatic Art, and she attended Hunter College.
Radio Banks first appeared on radio with Walter O"Keefe in 1936, when she was 18. Her roles on radio programs included the following: Film Banks married fellow actor Frank Lovejoy, whom she met when both had roles on the radio soap opera This Day Is Ours. The couple had two children, Judy and Steve.
Joan Banks died in Los Angeles, California in 1998 from lung cancer at the age of 79.
She was buried next to her husband in Holy Cross Cemetery in Culver City, California.
