Jay Vivian Chambers (April 1, 1901 – July 9, 1961), known as Whittaker Chambers, was an American editor and former Communist spy who eventually denounced his Communist spying and became respected by the American Conservative movement during the 1950s.
After early years as a Communist Party member (1925) and Soviet spy (1932–1938), he defected from communism (underground and open party) and worked at Time magazine (1939–1948). Under subpoena in 1948, he testified in what became Alger Hiss's perjury (espionage) trials (1949–1950) and he became an outspoken anti-communist (all described in his 1952 memoir Witness). Afterwards, he worked briefly as a senior editor at National Review (1957–1959). President Ronald Reagan awarded him the Presidential Medal of Freedom posthumously in 1984.