Aaron Siskind (December 4, 1903 – February 8, 1991) was an American photographer and was, with Harry Callahan, one of the greatest artist/photographers in history. Close friends with Mark Rothko, Franz Kline (whose own breakthrough show at the Charles Egan Gallery occurred in the same period as Siskind's one-man shows at the Egan Gallery), and De Kooning, he is widely considered to be closely involved with, if not a part of, the abstract expressionist movement.
He was a grade school English teacher in the New York Public School System for 25 years, and began photography when he received a camera for a wedding gift and began taking pictures on his honeymoon. Early in his career Siskind was a member of the New York Photo League, where he produced several significant socially conscious series of images in the 1930s, among them "Harlem Document".
Siskind's work focuses on the details of nature and architecture. He presents them as flat surfaces to create a new image which stands independent of the original subject. For some his work has been described as crossing the line between photography and painting, though like Harry Callahan's work, his photographs are works unique to the art form of photography.