Peter Valentinovich Turchin (; Russian: Пётр Валенти́нович Турчи́н, IPA: [ˈpʲɵtr vəlʲɪnʲˈtʲinəvʲɪtɕ tʊrˈtɕin]; born 22 May 1957) is a Russian-American complexity scientist, specializing in an area of study he and his colleagues developed called cliodynamics—mathematical modeling and statistical analysis of the dynamics of historical societies. Turchin is an emeritus professor at the University of Connecticut in the departments of ecology and evolutionary biology, anthropology, and mathematics. He is a project leader at the Complexity Science Hub Vienna and a research associate at the School of Anthropology of the University of Oxford. He was editor-in-chief and remains a member of the editorial board at Cliodynamics: The Journal of Quantitative History and Cultural Evolution. Turchin is a founding director of the Seshat: Global History Databank. He was a director of the Evolution Institute. In 2021, he was elected a fellow of the American Association for the Advancement of Science.