Patricia Mary O'Callaghan (born October 2, 1970) is a classically trained Canadian singer. She is a soprano who has built an international reputation as a performer of contemporary opera, early 20th-century cabaret music and the songs of Leonard Cohen. She trained as an opera singer after being unable as a teenager to decide whether to become a rockstar or a nun and JazzTimes magazine has labelled her "the stunning Canadian chanteuse with the chilling soprano voice".