Wilson was born in Burbank, California. She is the oldest daughter of Mike Wilson, a television broadcast engineer at KTLA-TV News and the late Suzie Shapiro Wilson, a homemaker and Burbank PTA school volunteer. Wilson's mother was Jewish, and her father is of part Irish descent. She was raised Jewish and became an atheist when she was 15. She has three older brothers—Danny, Jon, and Joel—and a younger sister, Anna. Political commentator Ben Shapiro is her maternal cousin. Her mother was diagnosed with breast cancer on March 10, 1995, and died on April 26, 1996. The film, Matilda, was dedicated to her memory. Wilson later recalled that this affected her passion for acting. Suzie Wilson is buried in Mount Sinai Memorial Park in Los Angeles, California.