Colonizing Christianity: Greek and Latin Religious Identity in the Era of the Fourth Crusade (Fordham University Press, 2019).
Christianity, Democracy and the Shadow of Constantine, eds. George Demacopoulos and Aristotle Papanikolaou (New York: Fordham University Press, 2017). Winner of 2017 Alpha Sigma Nu Award.
Gregory the Great: Ascetic, Pastor, and First Man of Rome (University of Notre Dame Press, 2015).
The Invention of Peter: Apostolic Discourse and Papal Authority in Late Antiquity (University of Pennsylvania Press, 2013).
Orthodox Constructions of the West, ed. by Demacopoulos and Papanikolaou (Fordham University Press, 2013).
Orthodox Readings of Augustine, ed. by Demacopoulos and Papanikolaou (St. Vladimir’s Seminary Press, 2008).
Five Models of Spiritual Direction in the Early Church (University of Notre Dame Press, 2007).