The Great Purge, a series of campaigns of political repression and persecution in the Soviet Union orchestrated by Joseph Stalin in 1936-1938, also described as a "Soviet holocaust" by several authors, involves the purge of the Communist Party of the Soviet Union, repression of peasants, Red Army leadership, and the persecution of unaffiliated persons, characterized by widespread police surveillance, widespread suspicion of "saboteurs", imprisonment, and killings.

Estimates of the number of deaths associated with the Great Purge run from the official figure of 681,692 to nearly 2,000,000.In Russian historiography the period of the most intense purge, 1937-1938, is called Yezhovshchina (literally, Yezhovism), after Nikolai Yezhov, the head of the Soviet secret police, NKVD.In the Western World the term "the Great Terror" will later be popularized by the title of Robert Conquest's book.

The book, The Great Terror, was in turn inspired by the period of the Great Terror (French: la Grande Terreur) at the end of the Reign of Terror during the French Revolution.