Gaylord Probasco Harnwell CBE (September 29 1903 - April 1982), was an American educator and physicist, who was president of the University of Pennsylvania from 1953 to 1970. He also held a great number of positions in a wide variety of national political and educational boards and committees, as well as senior positions in both the Office of the Governor of Pennsylvania and the United States Navy. In the later part of his life he also toured both the Soviet Union and Iran as a promoter of higher education.