Ruth Iouliani (Juliana) Macrides (1949 – 27 April 2019) was a UK-based historian of the Byzantine Empire. At the time of her death, she was Reader in Byzantine Studies at the Centre for Byzantine, Ottoman and Greek Studies at the University of Birmingham. She was an expert in Byzantine history, culture and politics, particularly of the mid-later Byzantine period, and of the reception of Byzantium in Britain and Greece.