Hiram Milliken Hiller Jr. (March 8, 1867 – August 8, 1921), was an American physician, medical missionary, explorer, and ethnographer. He traveled in Oceania and in South, Southeast, and East Asia, returning with archeological, cultural, zoological, and botanical specimens and data for museums, lectures and publications. His notes and collections provide valuable information about those regions and their people from the late 19th century. In later life, he was involved in the study of polio during the epidemics that hit the United States in the early 20th century.