Santa Teresa is an unincorporated community in Dona Ana County, New Mexico, United States. It is home to the Santa Teresa Port of Entry and is part of the Las Cruces Metropolitan Statistical Area, although geographically it is considerably closer to El Paso, Texas, than to Las Cruces. While the United States Census Bureau defined Santa Teresa as a census-designated place (CDP), the census definition of the area may not precisely correspond to local understanding of the area with the same name. The population was 4,258 at the 2010 census and 5,044 at the 2020 census. The National Weather Service El Paso Weather Forecast Office that serves extreme western Texas and Southwestern New Mexico states is based in Santa Teresa.