Sheila May Fitzpatrick is an Australian historian, whose main subjects are history of the Soviet Union and history of modern Russia, especially the Stalin era and the Great Purges, of which she proposes a "history from below", and is part of the "revisionist school" of Communist historiography. She has also critically reviewed the concept of totalitarianism and highlighted the differences between Nazi Germany and the Soviet Union in debates about comparison of Nazism and Stalinism.