Marcia Morris's scholarly training was in the area of medieval Russian literature and culture, and the transition from medieval to modern canons underlies much of her research. Her Saints and Revolutionaries: The Ascetic Hero in Russian Literature focuses on literary works created by Russians over the course of more than seven centuries and explores the interplay of religion, politics, and belles lettres in Russia. Her second monograph, The Literature of Roguery in Seventeenth- and Eighteenth-Century Russia, investigates the interweaving of native Russian and imported Western literary traditions. She is also the author of numerous articles on seventeenth- and eighteenth-century Russian literature.

Morris teaches a wide variety of courses ranging from introductory language to upper level literature and culture offerings in both Russian and English.