American photographer, best known for her compelling, often disturbing, portraits of people from the edges of society.

Diane Nemerov was the daughter of Gertrude Russek and David Nemerov, proprietors of a department store. Her older brother was the poet and critic Howard Nemerov (Nemerov, Howard). At age 18 she married Allan Arbus (divorced 1969), an employee at her family's store. Before separating, they worked collaboratively, first taking photographs and creating advertisements for the store, then creating commercial fashion photography for Harper's Bazaar, Show, Esquire, Glamour, The New York Times, and Vogue.

After taking a brief photography course with Berenice Abbott (Abbott, Berenice), Arbus met Lisette Model (Model, Lisette), an Austrian-born documentary photographer, and studied with her from about 1955 to 1957. With Model's encouragement Arbus gave up commercial work to concentrate on fine-art photography. In 1960 Esquire published Arbus's first photo-essay, in which she effectively juxtaposed privilege and squalor in New York City. Thereafter she made a living as a freelance photographer and photography instructor.

In 1963 and 1966 Arbus received Guggenheim fellowships to be part of a project titled “American Rites, Manners, and Customs.” During this period she mastered her technique of using a square format, which emphasizes the subject more than the photograph's composition. She also used flash lighting, which gives her work a sense of theatricality and surrealism. She began at that time to explore the subjects that would occupy her for much of her career: individuals living on the outskirts of society and “normalcy,” such as nudists, transvestites, dwarfs, and the mentally or physically handicapped. Her own evident intimacy with the extraordinary subjects of her photos resulted in images that engage the sympathy and collusion of the viewer and elicit a strong response. Some critics saw her work as remarkably empathetic to its subjects, while others were disturbed by what they saw as a harsh, voyeuristic look into the lives of the disadvantaged.

In 1971 Arbus committed suicide. A collection of her photos was published in 1972 in connection with a successful major exhibition of her work at the Museum of Modern Art in New York City. That same year her work was shown at the Venice Biennale, marking the first time that an American photographer received that distinction. In 2003 an extensive exhibition of her work opened at the San Francisco Museum of Modern Art and later traveled throughout the United States and Europe. An accompanying book, Diane Arbus Revelations (2003), contained some 200 photographs as well as excerpts from her letters and notebooks. In 2007 Arbus's estate gifted her complete archives—including photographic equipment, diary pages, and the negatives of some 7,500 rolls of film—to the Metropolitan Museum of Art in New York City.