Harris teaches courses in Old English, medieval Latin, and historical linguistics. He is also involved in HFA's Initiative in Data Science in the Humanities (DaSH) for which he teaches an introductory course in data science. Harris was awarded grants from the Fulbright Foundation, the Social Sciences and Humanities Research Council of Canada, the National Endowment for the Humanities, and the Mellon Foundation. He is the Editor of the journal, Old English Newsletter. He served as chair of the Modern Language Association’s Old English Division and its Old Norse Group.
- Race and Ethnicity in Anglo-Saxon Literature (Routledge, 2003)
- Misconceptions about the Middle Ages (Routledge, 2008), edited with Bryon Grigsby;
- Vox Germanica: Essays on Germanic Literature and Culture in Honor of James E. Cathey, edited with Michael Moynihan and Sherrill Harbison (University of Arizona, 2013).
- Bede and Aethelthryth: An Introduction to Christian Latin Poetics (West Virginia, 2016).