John Gilmore (September 28, 1931 – August 20, 1995) was an American jazz saxophonist, clarinetist, and percussionist. He was known for his tenure with the avant-garde keyboardist/bandleader Sun Ra from the 1950s to the 1990s.

Gilmore was raised in Chicago and played clarinet from the age of 14. He took up the tenor saxophone while serving in the United States Air Force from 1948 through 1951. He then pursued a musical career, beginning as a tenor saxophonist on a national tour with the Harlem Globetrotters in an ensemble that included pianist Earl Hines in 1952.

In 1953 Gilmore met pianist and bandleader Sun Ra who had a profound impact on him as a musician. For the next four decades, he recorded and performed almost exclusively with Sun Ra; first as a trio, and then in the band Arkestra. This was puzzling to some, who noted Gilmore’s talent, and thought he could be a major star like John Coltrane or Sonny Rollins. Despite being five years older than Gilmore, Coltrane was impressed with his playing, and took informal lessons from Gilmore in the late 1950s. Coltrane’s epochal, proto–free jazz “Chasin’ the Trane” was inspired partly by Gilmore’s sound. The Penguin Guide to Jazz suggests Gilmore remained an influence in Coltrane’s later period, particularly on Sun Ship.