John Kirby (December 31, 1908 – June 14, 1952), was an American jazz double-bassist, who also played trombone and tuba. In addition to sideman work (prominently with Benny Goodman), Kirby is remembered for leading a successful chamber jazz sextet in the late 1930s and early 1940s, which scored several hit songs including "Loch Lomond" and the debut recording of "Undecided", a jazz standard. He is perhaps the first musician in the chamber jazz genre.