Rachael MacFarlane (born March 21, 1976) is an American voice actress and is the sister of Family Guy creator and producer, Seth MacFarlane. She was the original voice of Meg Griffin, voicing her in the Pilot Pitch. She currently voices many female characters, notably Olivia. In "The Former Life of Brian", she provides the voice of a teenage Tracy Flannigan. She also voices Hayley Smith on American Dad!.