Atascosa ( AT-əs-KOH-sə) is an unincorporated community located in southwest Bexar County, Texas, United States. Atascosa is 14 miles southwest of downtown San Antonio. It is located between Von Ormy and Lytle, Texas off I-35. The community is part of the San Antonio Metropolitan Statistical Area.
The Atascosa post office (78002) opened in 1872 and is located today on Old Pearsall Road at Jarratt Road. In 1885 the community had a Baptist church, a district school, a general store, a saloon, two blacksmiths, and a population of 180. A coal mine was in operation by 1900.
Atascosa is located at 29°17.14′N 98°38.84′W and is 41.97 square miles.
As of the 2010 U.S. Census, there were 8,735 people residing in this populated place. The population density was 208 people per square mile.