Grant County is a county located in the U.S. state of New Mexico. At the 2020 census, the population was 28,185. Its county seat is Silver City. The county was founded in 1868 and named for Ulysses S. Grant, the 18th President of the United States. Grant County comprises the Silver City, NM, Micropolitan Statistical Area. It is part of the Southwest New Mexico Council of Governments.