South Versailles Township is a township in Allegheny County, Pennsylvania, United States. The population was 351 at the 2010 census. Early in its history, South Versailles contained three villages known as Coulter, Emblem, and Osceola. The village of Coulter is also called Coulterville or Coulters. The U.S. Post Office in the village is called Coulters.
The township derives its name from the Palace of Versailles.
The township is a narrow strip of land located on the right (east) bank of the Youghiogheny River, between it and the Westmoreland County line. It contains two tiny villages, Alpsville and Coulter, plus a couple of small coal strip mines.
According to the United States Census Bureau, the township has a total area of 1.0 square mile (2.6 km2), of which 0.9 square miles (2.3 km2) is land and 0.1 square miles (0.26 km2), or 12.24%, is water.
South Versailles has two land borders with White Oak to the north and North Huntingdon Township in Westmoreland County to the east. Across the Youghiogheny River to the west, South Versailles runs adjacent with Elizabeth Township.
As of the census of 2000, there were 351 people, 151 households, and 107 families residing in the township. The population density was 407.6 people per square mile (157.6/km²). There were 162 housing units at an average density of 188.1/sq mi (72.7/km²). The racial makeup of the township was 100.00% White. Hispanic or Latino of any race were 0.28% of the population.