Growing up, Banks played baseball and rode horses. She was in Little League when she broke her leg sliding into third base. She then tried out for the school play, which was her start in acting. She graduated from Pittsfield High School in 1992, and is a member of the Massachusetts Junior Classical League. She attended the University of Pennsylvania, where she was a member of the Delta Delta Delta Sorority and was elected to the Friars Senior Society. She graduated magna cum laude in 1996 with a major in communications and a minor in theater arts. In 1998, she completed schooling at the American Conservatory Theater in San Francisco, California, where she earned an MFA degree.