Tom Coster (born August 21, 1941) is an American keyboardist, composer, and longtime backing musician for Carlos Santana.

[1] Detroit-born and San Francisco-raised, Coster played piano and accordion as a youth, continuing his studies through college and a productive five-year stint as a musician in the U.S. Air Force Band.

Coster has played with and/or composed for many groups and musicians including The Loading Zone, Gábor Szabó, Carlos Santana, Billy Cobham, Third Eye Blind, Coryell/Coster/Smith, Claudio Baglioni, Stu Hamm, Boz Scaggs, Zucchero and Bobby Holiday, Joe Satriani, Frank Gambale, and Vital Information.

Coster also produced several solo jazz fusion recordings as a leader for Fantasy, Headfirst, and JVC.

Some of Coster's best-known compositions are "Europa (Earth's Cry Heaven's Smile)", "Flor D'Luna (Moonflower)" and "Dance, Sister, Dance (Baila Mi Hermana)" performed by Santana and "The Perfect Date" performed by Vital Information.