Arthur Kingsley Porter (1883–1933) was an American archaeologist, art historian, and medievalist. He was chair of Harvard University’s art history department, and was the first American scholar of Romanesque architecture to achieve international recognition. Porter disappeared in 1933. His most significant scholarly contributions were his revolutionary studies and insights into the spread of Romanesque sculpture. His study of Lombard architecture also remains the first in its class. He left his Cambridge mansion, Elmwood, to Harvard University, where it has served as the official residence of Harvard's president since 1970.