Leonard Warren (April 21, 1911 - March 4, 1960) was a famous American opera singer. A baritone, he was associated for many years with the Metropolitan Opera in New York. Soprano Renata Tebaldi said of his voice: "it was a very, very soft, velvety voice...He was truly stupendous." The actor and opera fan Tony Randall said Warren's voice was "huge" and it filled the Metropolitan Opera theatre "like black smoke."