Aaron Siskind (December 4, 1903 – February 8, 1991) was an American photographer whose work focuses on the details of things, presented as flat surfaces[1] to create a new image independent of the original subject.

He was closely involved with, if not a part of, the abstract expressionist movement, and was close friends with painters Franz Kline (whose own breakthrough show at the Charles Egan Gallery occurred in the same period as Siskind's one-man shows at the same gallery), Mark Rothko, and Willem de Kooning.

[4][5] Early in his career Siskind was a member of the New York Photo League,[1] where he produced several significant socially conscious series of images in the 1930s, among them "Harlem Document",[6][7] a book published in 1981 featuring a collection of 52 photographs, including portraits of residents, as well as photographs of street and domestic life in Harlem.

[8] Along with the photographs, the book features interviews, stories and rhymes collected by members of the Federal Writers’ Project.

Later, Callahan persuaded Siskind to join him as part of the faculty of the IIT Institute of Design in Chicago[1] (founded by László Moholy-Nagy as the New Bauhaus[12]).

Siskind used subject material from the real world: close-up details of painted walls and graffiti, tar repair on asphalt pavement, rocks, lava flows, dappled shadows on an old horse, Olmec stone heads, ancient statuary and the Arch of Constantine in Rome, and a series of nudes ("Louise").