James Mortimer Southwick (July 10, 1846 - June 3, 1904) was an American naturalist and educator who lived in Providence. He established a natural history store and founded the periodical Random Notes on Natural History (1884–86). After selling off his natural history store in 1896 he served as a curator of the Roger Williams Park Museum and served as a State Entomologist. He was the first to note the differences between the willet populations in North America, leading to the description of the subspecies inornata by William Brewster.