Alexander Hamilton Rice Jr. (August 29, 1875 – July 23, 1956) was an American physician, geographer, and explorer especially noted for his expeditions to the Amazon Basin. He was a professor of geography at Harvard University from 1929 to 1952, and was the founder and director of the Harvard Institute of Geographical Exploration. He was also the curator of the South American Section of the Peabody Museum of Archaeology and Ethnology.