Warren Upham (8 March 1850 – 29 January 1934) was a geologist, archaeologist, and librarian who is best known for his studies of glacial Lake Agassiz. Upham worked as a geologist in New Hampshire before moving in 1879 to Minnesota to study the resources and glacial geology of that state. Upham's first major report on Lake Agassiz was published in 1890 by the Geological Survey of Canada, but the main product of his many years of study ("The Glacial Lake Agassiz") was published in 1895 as Monograph 25 of the U.S. Geological Survey's monograph series.