Kyes attended high school in Riverside, California, and studied theatre at Northwestern University in Evanston, Illinois. Before starring in Halloween, she played Julie in the 1976 thriller Assault on Precinct 13, also directed by Carpenter. In addition to acting, she served as this film's wardrobe mistress, but she used a different name for the film credits ("Louise Kyes" for the wardrobe mistress credit and "Nancy Loomis" for her acting credit). Although she has starred in a few TV movies, her only guest appearance on television was on the 1985 revivial of The Twilight Zone.