American composer Gunther Schuller (born 1925) is a composer and horn player. He is regarded as one of the key figures in contemporary classical music.

He studied at the Saint Thomas Choir School and became an accomplished horn player; at the age of seventeen he was principal hornist with the Cincinnati Symphony, and two years later took up a similar position with the Metropolitan Opera Orchestra. In 1959 he gave up performance to devote himself to composition. He has conducted internationally and studied and recorded jazz with such greats as Dizzy Gillespie, Miles Davis, and John Lewis. He coined the term "Third Stream" to describe music that combines classical and jazz techniques. Schuller has written over 160 original compositions. In the 1960's, Schuller was president of New England Conservatory. He created the jazz program at NEC, which today is one of the strongest jazz centers in the world.

His notable students include Eric Ewazen and Daniel Asia.