Blue (also Whittum) is an unincorporated community in Greenlee County, Arizona, United States. It lies 33°36′36″N 109°6′24″W / 33.61°N 109.10667°W / 33.61; -109.10667 (33.6100552, -109.1067396), at an elevation of 5,758 feet (1,755 m). The community was originally named for Nat Whittum, an original settler who was killed at the site in 1891. A post office was established at Whittum in 1894; however, its name was changed to Blue in 1898, because everyone knew where the Blue River was but Whittum was not known.