Bob Graettinger was an American composer, best known for his work with Stan Kenton.

Graettinger grew up in Ontario, California, learning to play the saxophone in high school. While at school he also began arranging music. In the 1940s he played alto sax with Benny Carter among others. Around this time he focused more on composing.

In 1947 he offered a short composition, "Thermopylae", to Stan Kenton, who decided to record it. Graettinger then came up with "City of Glass", a four-part tone poem. At this time he was studying composition under Russell Garcia.

Graettinger's radical polystylistic soundworld, with its polyphonic density and bracing atonality, while drawing on ideas previously explored by the likes of Charles Ives, Igor Stravinsky Aaron Copland and even Arnold Schoenberg, still remains truly distinctive. He died aged only 33, of lung cancer.