Elie Siegmeister (January 15, 1909–March 10, 1991) was an American composer, educator and author. His varied musical output showed his concern with the development of an authentic American musical vocabulary. Jazz, blues and folk melodies and rhythms are frequent themes in his many song cycles, his nine operas, his nine symphonies and his chamber works. He also composed for Hollywood and Broadway, and sometimes wrote under the pseudonym LE Swift.
Siegmeister was among the numerous American composers, including Aaron Copland, Virgil Thomson, Leonard Bernstein and others, who were students of the influential teacher Nadia Boulanger in Paris. His own students included Leonard J. Lehrman.
He was born in New York City, and died in Manhasset, Long Island.