Martin's Lie is a chamber opera in one act with music and an English language libretto by Gian Carlo Menotti. Commissioned by CBS, it was Menotti's third opera for television after Amahl and the Night Visitors and Labyrinth. Although not initially conceived as a work for the stage, the opera premiered in a live theatrical performance on 3 June 1964 at the Bristol Cathedral for the opening of the 17th annual Bath International Music Festival. The opera was subsequently filmed with the same cast for television under the direction of Kirk Browning. The production used sets and costumes by designer Anthony Powell, and was broadcast nationally by CBS for the opera's United States premiere on 30 May 1965.