Anthony John Medeski (born 28 June 1965) is an American keyboard player and composer. He studied classical piano and attended the New England Conservatory before moving to NYC. Medeski is a veteran of New York's 1990s avante-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.

A visible part of NYC's "downtown" scene, Medeski has performed in numerous configurations with artists such as John Zorn, John Scofield, Marc Ribot, John Lurie and Steven Bernstein.

Medeski's recording credits include Iggy Pop, T-Bone Burnett, Ray Lamontagne, Dan the Automator. He also produced the first two albums for The Wood Brothers and The Dirty Dozen Brass Band.

Medeski continues to record and tour rigorously with Medeski Martin & Wood. Recently, he went on tour with his side project, THE WORD, which consists of pedal steel guitarist Robert Randolph and the North Mississippi AllStars.