William John Evans, known as Bill Evans (pronunciation: /ˈɛvəns/, August 16, 1929 – September 15, 1980), was an American jazz pianist and composer who mostly worked in a trio setting. He is widely considered to be one of the greatest jazz pianists of all time, and is considered by some to have been the most influential post-World War II jazz pianist. Evans's use of impressionist harmony, inventive interpretation of traditional jazz repertoire, block chords, and trademark rhythmically independent, "singing" melodic lines continue to influence jazz pianists today. Unlike many other jazz musicians of his time, Evans never embraced new movements like jazz fusion or free jazz.

Born in Plainfield, New Jersey, Evans was classically trained, and studied at Southeastern Louisiana University. In 1955, he moved to New York, where he worked with bandleader and theorist George Russell. In 1958, Evans joined Miles Davis's sextet, where he was to have a profound influence. In 1959, the band, then immersed in modal jazz, recorded Kind of Blue, the best-selling jazz album of all time.