A Great Day in Harlem or Harlem 1958 is a black-and-white photograph of 57 jazz musicians in Harlem, New York, taken by freelance photographer Art Kane for Esquire magazine on August 12, 1958. The idea for the photo came from Esquire's art director, Robert Benton, rather than Kane. However, after being given the commission, it seems the latter was responsible for choosing the location for the shoot. The subjects are shown at 17 East 126th Street, between Fifth and Madison Avenue, where police had temporarily blocked off traffic. Published as the centrefold of the January 1959 ("Golden Age of Jazz") issue of Esquire, the image was captured with a Hasselblad camera, and earned Kane his first Art Directors Club of New York gold medal for photography. It has been called "the most iconic photograph in jazz history".

The scene portrayed is something of an anachronism, as by 1957 Harlem was no longer the "hotbed" of jazz it had been in the 1940s, and had "forfeited its place in sun" to 52nd Street in Midtown Manhattan. Many musicians who were formerly resident in the area had already moved to middle class parts of New York, or did so shortly thereafter. Kane himself was not that certain who would turn up on the day, as Esquire staff had merely issued a general invitation through the local musicians' union, recording studios, music writers, and nightclub owners.

In 2018, a book was published to mark the 60th anniversary of the event, with forewords by Quincy Jones and Benny Golson, and an introduction by Kane's son, Jonathan.