Fr. Louth's collegiate education was at the Universities of Cambridge and Edinburgh where he studied Mathematics and Theology and prepared his thesis which concerned Karl Barth. After graduation he taught early Christian theology and patristics in the University of Oxford and early Medieval and Byzantine history Goldsmiths College in the University of London.
Fr. Louth has been Professor of Patristic and Byzantine Studies at Durham University since 1996. He teaches courses on the history and theology of the Christian Church: an undergraduate module dealing with the impact of the rise of Islam on mostly Greek Christianity in the eastern Mediterranean and a Master of Arts module on the understanding of what it is to be human in early Christian theology.
His interests in research lie mostly in the history of theology in the Greek tradition, especially in periods later than what is usually studied in the universities of England; that is, after the fifth century during the period of the Byzantine Empire to 1453. He is also interested in later periods including the modern period; that is the nineteenth century and later, where his research includes Russian and Romanian Orthodox theology.