Anthony Blunt, English historian and spy (d. 1983)
Anthony Frederick Blunt (26 September 1907 – 26 March 1983), styled Sir Anthony Blunt KCVO from 1956 to November 1979, was a leading British art historian who in 1964, after being offered immunity from prosecution, confessed to having been a spy for the Soviet Union.

Blunt was considered to be the "fourth man" of the Cambridge Five, a group of Cambridge-educated spies working for the Soviet Union from some time in the 1930s to at least the early 1950s. He was the fourth discovered, with John Cairncross yet to be revealed. The height of his espionage activity was during World War II, when he passed intelligence on Wehrmacht plans that the British government had decided to withhold from its ally. His confession, a closely guarded secret for years, was revealed publicly by Prime Minister Margaret Thatcher in November 1979. He was stripped of his knighthood immediately thereafter.

Blunt was professor of art history at the University of London, director of the Courtauld Institute of Art, and Surveyor of the Queen's Pictures. His 1967 monograph on the French Baroque painter Nicolas Poussin is still widely regarded as a watershed book in art history. His teaching text and reference work Art and Architecture in France 1500–1700, first published in 1953, reached its fifth edition in a slightly revised version by Richard Beresford in 1999, when it was still considered the best account of the subject.