Katharine Keats-Rohan is a medievalist who has published widely over the past twenty years. Her earliest work was in intellectual history. The work of the twelfth-century bishop and thinker, John of Salisbury, is the primary focus of her own research, she has also worked on Peter Abelard with Professor David Luscombe at Sheffield University. She has also undertaken a major inquiry into the Continental Origins of English Landholders 1066-1166, seeking the origins of the men who conquered England in 1066 or settled here thereafter.

This work built upon her research interests in north-west France, which include studies of Brittany and Maine and the community of the abbey of Mont-Saint-Michel. Interests closer to home include the medieval borough of Wallingford, of which a history is projected. She is closely associated with prosopography as a historical method, directing the Unit for Prosopographical Research at Linacre College, Oxford, since 1993 .

Together with Christian Settipani, of the CNRS group L’Année Epigraphique, she established Prosopographica et Genealogica as an imprint of the Unit. Also a founding member in 2003 of a joint Oxford-Trier group, Netwerk Interferenzonomastik (NIO) (Network for Research on Interference and Interculturalization in Onomastics), based at the University of Trier. She became a Fellow of the Royal Historical Society in 2002.