George Robert Ackworth Conquest (born July 15, 1917) is a British historian who became a well-known writer and researcher on the Soviet Union with the publication in 1968 of The Great Terror, an account of Stalin's purges of the 1930s.

Upon its publication in 1968, Conquest's The Great Terror: Stalin's Purge of the Thirties ( LJ 12/1/68) received wide acclaim for its broad, well-documented portrayal of the death of millions in Stalin's peacetime consolidation of power. A generation later, the collection of samizdat literature and the openness of glasnost have permitted access to better information, thereby allowing a reassessment of the study. Conquest's review largely confirms the original work. In the new edition more recent documentation is incorporated and some portions are revised based upon new data. However, the substance of the text is much the same. Outdated appendixes have been removed. This remains an essential source, and any library without it should buy it. Larger collections will want the revision.