Simpsonville is a city in Greenville County, South Carolina, United States. It is part of the Greenville–Mauldin–Easley Metropolitan Statistical Area. The population was 18,238 at the 2010 census, up from 14,352 in 2000. The population had risen to an estimated 20,736 as of 2015. Simpsonville is part of the "Golden Strip", along with Mauldin and Fountain Inn, an area which is noted for having low unemployment due to a diversity of industries including Para-Chem, Kemet, Sealed Air and Milliken.