John Aaron Lewis (1920-2001) was an American jazz pianist and composer best known as the musical director of the Modern Jazz Quartet.
Before recording with the Milt Jackson Quartet in 1951 he had performed or recorded with Charlie Parker, Dizzy Gillespie, Illinois Jacquet, Miles Davis, and Lester Young. The Modern Jazz Quartet developed out of the Jackson quartet; Lewis was its musical director till it disbanded in 1974 and after it reorganized in 1981.
He was also an educator and composer of movie scores.