She is an expert on the Frankish kingdoms in the eighth and ninth centuries AD, who uses palaeographical and manuscript studies to illuminate aspects of the political, cultural, intellectual, religious, and social history of the Early Middle Ages.

[1] She is a Fellow of Sidney Sussex College and Professor Emerita of Medieval History in the University of Cambridge.

McKitterick has been described as a "doyenne in her field; her decades of tireless research and teaching have been poured into a steady stream of major publications on Carolingian subjects.

"[5] Thomas F. X. Noble considers McKitterick to be "one of the most original and productive historians of Europe's early Middle Ages".

[8] In 2010 McKitterick was awarded the Dr A. H. Heineken International Prize for History by the Royal Dutch Academy.

In 2015 McKitterick was elected to the Lectio Chair at the Katholieke Universiteit of Leuven's Centre for the Transmission of Texts and Ideas in Antiquity, the Middle Ages, and the Renaissance.

[14] On 15 October 2018 McKitterick delivered the James Lydon Lecture in Medieval History and Culture at Trinity College Dublin with "Rome and the Invention of the Papacy in the Early Middle Ages".