South Mountain is a town in Coryell County, Texas, United States.

According to the United States Census Bureau, the town of South Mountain has a total area of 1.6 square miles (4.2 km2), all land.

There were 161 housing units at an average density of 98.8 per square mile (38.1/km2).

13.0% of all households were made up of individuals, and 2.7% had someone living alone who was 65 years of age or older.

[7] All of the county is in the service area of Central Texas College.