Sunland Park is a city in southern Doña Ana County, New Mexico, United States, on the borders of Texas and the Mexican state of Chihuahua, with Ciudad Juárez adjoining it on the south and El Paso, Texas, on the east. The community of Santa Teresa adjoins it on the northwest. The population of Sunland Park was 14,106 at the 2010 census and was estimated at 17,978 by the United States Census Bureau in 2019. Though it lies adjacent to El Paso, being in Doña Ana County makes it a part of the Las Cruces metropolitan statistical area. Las Cruces is 42 miles (68 km) to the north.

Doña Ana County is located in the southern part of the State of New Mexico, United States. As of the 2020 U.S. Census, its population was 219,561, which makes it the second-most populated county in New Mexico. Its county seat is Las Cruces, the second-most populous municipality in New Mexico after Albuquerque, with 111,385 as of the 2020 U.S. Census.