Thomas Williams is the Isabelle A. and Henry D. Martin Professor of Medieval Philosophy at Georgetown University. He has published widely on medieval philosophy and theology, with a particular focus on Augustine, Anselm, Thomas Aquinas, and John Duns Scotus.

His work includes Anselm: A Very Short Introduction, Anselm: The Complete Treatises with Selected Letters and Prayers and the Meditation on Human Redemption, and a translation of Augustine' Confessions.