"Anthony John Medeski (born June 28, 1965) is an American jazz keyboards player and composer. Medeski is a veteran of New York's 1990s avant-garde jazz scene and is known popularly as a member of Medeski Martin & Wood. He plays the acoustic piano and an eclectic array of keyboards, including the Hammond B3 organ, melodica, mellotron, clavinet, ARP String Ensemble, Wurlitzer electric piano, Moog Voyager Synthesizer, Wurlitzer 7300 Combo Organ, Vox Continental Baroque organ, and Yamaha CS-1 Synthesizer (a "kids' toy"), among others. When playing acoustic piano, Medeski usually plays the Steinway piano and is listed as a Steinway Artist.

Medeski was born in Louisville, Kentucky, and grew up in Florida. After studying piano as a child (starting when he was five years old), he began as a teenager to perform with musicians such as Mark Murphy and Jaco Pastorius. He attended Pine Crest School. In 1983, after graduating from high school, he began studying piano at the New England Conservatory in Boston, where he performed as a sideman with Dewey Redman, Billy Higgins, Bob Mintzer, Alan Dawson and Mr. Jellybelly. Medeski attributes his early interest in playing improvised music and jazz to listening to Oscar Peterson."