John Aaron Lewis (May 3, 1920 – March 29, 2001) was an American jazz pianist, composer and arranger, best known as the founder and musical director of the Modern Jazz Quartet.

John Lewis was born in La Grange, Illinois, and after his parents’ divorce moved with his mother, a trained singer, to Albuquerque, New Mexico when he was two months old. She died from peritonitis when he was four and he was raised by his grandmother and great-grandmother. He began learning classical music and piano at the age of seven. His family was musical and had a family band that allowed him to play frequently and he also played in a Boy Scout music group. Even though he learned piano by playing the classics, he was exposed to jazz from an early age because his aunt loved to dance and he would listen to the music she played. He attended the University of New Mexico, where he led a small dance band that he formed and double majored in Anthropology and Music. His piano teacher at the university was Walter Keller, to whom he paid tribute on the title composition of the Modern Jazz Quartet’s 1974 album In Memoriam.