Warren T. Treadgold (born April 30, 1949, Oxford, England) is an American historian and specialist in Byzantine studies. He is the National Endowment for the Humanities Professor of Byzantine Studies at Saint Louis University. His interest in the political, economic, military, social, and cultural history of the Byzantine Empire extends to the Byzantine historians themselves. Treadgold has also taught at UCLA, Stanford, Hillsdale, Berkeley, and Florida International University. He is married since September 25, 1982 to Irina Andreescu-Treadgold.