Since 1989 Ioli Kalavrezou has been the Dumbarton Oaks Professor of Byzantine Art History at the department of History of Art and Architecture at Harvard University, having earlier taught at UCLA and at the Ludwig Maximilian University in Munich. She has served as Chair of the department for six years and is also a Senior Fellow at Dumbarton Oaks. She is a member of the Executive Committee and Senior Research Associate at Dumbarton Oaks. She also serves as Trustee at the Cyprus Institute in Nicosia.

Of special interest in her research are topics in political and ideological history, as for example the relationship of Church and State, and the use of King David in imperial propaganda especially in manuscript illustrations. These questions lead her to investigate the visual evidence ranging from monumental wall paintings and mosaics to objects carved in ivory and steatite, icons, and manuscripts. Another topic of special research interest has been the cult of the Virgin Mary, which has also produced two Ph.Ds. now professors at Stanford and Berkeley.  Everyday life and private devotion have been areas of as for example published in her book on Byzantine Icons in Steatite. The sun imagery in the person of the emperor is her most recent project. The study of the role and place of women in Byzantine society produced in a large exhibition here at Harvard entitled Byzantine Women and their World and its catalogue.