Leon Lishner (4 July 1913 - 21 November 1995) was an American operatic bass-baritone. He was particularly associated with the works of Gian Carlo Menotti, having created parts in the world premieres of four operas by that composer. He performed in many productions with the New York City Opera and the NBC Opera Theatre during the 1950s and early 1960s.
Born in New York City, Lishner was the son of Russian Jewish immigrants to the United States. He earned diplomas in music from the City College of New York and the Juilliard School. In 1942-1943 he was committed to Sylvan Levin's Philadelphia Opera Company; performing the roles of Arkel in Pelléas et Mélisande, Colline in La bohème, Doctor Blind in Die Fledermaus, and Doctor Bartolo in The Marriage of Figaro. After appearing in supporting roles in several operas with a variety of companies, his first prominent stage part was the Chief Police Agent in the world premiere of Gian Carlo Menotti's The Consul in Philadelphia in 1950. He continued with the production when it moved to Broadway later that year. He also reprised the part in 1953 in concert with the Philadelphia Orchestra and in 1957 at Public Garden in Boston.
After the critical success of The Consul, Menotti was invited by NBC to compose an opera for television which was to be performed by the newly created NBC Opera Theatre (NBCOT). What resulted was the highly successful Christmas opera Amahl and the Night Visitors which was premiered on Christmas Eve of 1951 in a national broadcast to millions. For this production, Menotti enlisted the forces of many of the singers from The Consul; including Lishner who was cast in the role of King Balthazar. He continued to portray that role, along with the other original adult cast members, for annual live television broadcasts up through 1964. They also gave annual national tours of Amahl, performing with symphony orchestras in concerts throughout the United States.