Stu Williamson (May 14, 1933 – October 1, 1991) was an American jazz trumpeter and valve trombonist. Born in Brattleboro, Vermont, Williamson was the younger brother of jazz pianist Claude Williamson.
In 1949, he moved to Los Angeles, where he worked with Stan Kenton, Woody Herman, Billy May, Charlie Barnet, and Shelly Manne. He worked often as a session musician until his retirement in 1968. He battled drug addiction for much of his life and died in Studio City, California in 1991.