Fyodor Ivanovich Uspensky or Uspenskij (Russian pronunciation: [ˈfʲɵdər ɪˈvanəvʲɪtɕ ʊsʲˈpʲɛnskʲɪj]; Russian: Фёдор Иванович Успенский) was a Russian Empire and Soviet Byzantinist. His works are considered to be among the finest illustrations of the flowering of Byzantine studies in the Russian Empire.