Shipka was born in Chicago, Illinois, to John Young Shipka, a real estate developer, and his wife, Erin Ann (née Brennan), a one-time queen of Chicago's St. Patrick's Day parade. The family relocated to Los Angeles when she was six to support her acting career. Kiernan got her black belt in taekwondo in June 2012. Shipka's hobbies include golf and cooking and she enjoys watching Barefoot Contessa and Good Eats on the Food Network. She has been taking ballroom dancing classes since age five and claims Grace Kelly as an inspiration.