Georgy Alexandrovich Ostrogorsky (Russian: ???´???? ??????´??????? ???????´?????; 19 January 1902 – 24 October 1976), known in Serbian as Georgije Ostrogorski (Serbian Cyrillic: ???????? ???????????) and English as George Ostrogorsky, was a Russian-born Yugoslavian historian and Byzantinist who acquired worldwide reputations in Byzantine studies.