Gladstone is an unincorporated community in Union County, New Mexico, United States, founded in 1880. It lies at the intersection of US Route 56 and Union County Road C001. The post office, which opened in 1888, closed in 2010.
Gladstone was founded in 1880 by William H. Harris, an Englishman, who hoped to set up a Utopian religious community called "Gladstone Colony". He named it in honor of William Ewart Gladstone, a Liberal politician and the British Prime Minister at the time. A fair number of settlers came to Gladstone, but many left disillusioned shortly thereafter.
According to the Köppen Climate Classification system, Gladstone has a semi-arid climate, abbreviated "BSk" on climate maps. The hottest temperature recorded in Gladstone was on June 29, 1957, while the coldest temperature recorded was on January 13, 1963.