John Duffy is a native of Ireland who studied Classics at Maynooth College and at University College Dublin. Professor Duffy did his doctoral work at Buffalo under the guidance of L. G. Westerink.
The main focus of his research has been on Byzantine literature in the areas of theology, philosophy, medicine, and religious tales. One of his specialties is the preparation of text editions, a type of research he believes to be of fundamental importance for Medieval Greek which, in the matter of reliable texts, lags far behind not only Classics but Medieval Latin as well.
Among his publications are Synodicon Vetus, ed. and trans. with J. Parker (Dumbarton Oaks Texts, 1979); Stephanus the Philosopher, A Commentary on the Prognosticon of Hippocrates (Corpus Medicorum Graecorum, Berlin, 1983); Gonimos: Neoplatonic and Byzantine Studies Presented to Leendert G. Westerink at 75, ed. with J. Peradotto (Buffalo, 1988); Michael Psellos, Philosophica Minora I (Bibliotheca Teubneriana, Stuttgart/Leipzig, 1992); John of Alexandria, Commentary on Hippocrates' Epidemics VI, (Corpus Medicorum Graecorum, Berlin 1997); Michael Psellos, Theologica II, ed. with L. G. Westerink (Bibliotheca Teubneriana, Munich/Leipzig, 2002); Nicetas David, The Life of Patriarch Ignatius, text and tr. by A. Smithies, with notes by J. M. Duffy, Dumbarton Oaks Texts XIII, (Washington DC, 2013).
Projects underway include a critical edition, for the Corpus Christianorum series, of the homilies of Sophronius of Jerusalem, as well as the first edition of two ninth century treatises on icon veneration for the same series. He is also preparing an edition of Michael Psellos' commentary on the De interpretatione of Aristotle, in collaboration with K. Ierodiakonou.
Professor Duffy has been a Junior Fellow at Dumbarton Oaks (1971-73) and an Alexander von Humboldt Fellow at the Freie Universität Berlin (1984; 1987); he is a member of the following: the Kommission für das Corpus Fontium Historiae Byzantinae, the board of Senior Fellows in Byzantine Studies at Dumbarton Oaks, and the U.S. National Committee for Byzantine Studies. Since 2005, he has been editor of the Washington series of the Corpus Fontium Historiae Byzantinae. In 1999 he was the recipient of the Paideia Award from the Greek Archdiocese of America.