Judith Coplon Socolov (May 17, 1921 – February 26, 2011) was a spy for the Soviet Union whose trials, convictions, and successful constitutional appeals had a profound influence on espionage prosecutions during the Cold War. In 1949, three major cases against communists started in the United States: that of Coplon (1949–1967), that of Alger Hiss and Whittaker Chambers (1949–1950), and that of the Smith Act trials of Communist Party leaders (1949–1958).