The Theodor Mommsen Society at the Catholic University of America was founded to encourage learning, instruction, collaboration, and research in classics, late antiquity, law, and medieval culture, east and west. Practically, this means hosting meetings and seminars on topics various and sundry. It is an association of graduate students from many schools and departments: Greek and Latin, the Center for Medieval and Byzantine Studies, the Center for the Study of Early Christianity, the school of Theology, the school of Philosophy, the school of Canon Law, History, English, and Semitics.

The graduate student community at the Catholic University is large and diverse, and the Society aims to foster unity and collegiality among those interested, professionally or not, in classical and medieval culture.

At present members of the society are interested in late antiquity, medieval legal traditions, especially canon law, philology (from Latin to Old and Middle English), medieval science, medieval political theory, early Christian writers, Aquinas, rhetoric, Arthurian legends and literature, the poetry of the troubadours, Roman law, ecclesiastical history, paleography, hagiography, medieval women writers, and Byzantium in the early Middle Ages.

Informal society meetings are held twice a week in the Center for Medieval and Byzantine Studies in McMahon Hall. See the calendar below for more details.