Summerville is a town in the U.S. state of South Carolina situated mostly in Dorchester County with small portions in Berkeley and Charleston counties. It is part of the Charleston-North Charleston-Summerville Metropolitan Statistical Area. The population of Summerville at the 2010 census was 43,392, and the estimated population was 52,549 as of July 1, 2019.
The center of Summerville is in southeastern Dorchester County; the town extends northeast into Berkeley and Charleston counties. It is bordered to the east by the town of Lincolnville and to the southeast by the city of North Charleston. The Summerville town limits extend south as far as the Ashley River next to Old Fort Dorchester State Historical Park.
U.S. Route 78 passes near the center of Summerville, leading southeast 24 miles (39 km) to downtown Charleston and northwest 29 miles (47 km) to Interstate 95 at St. George. Interstate 26 leads through the northeast corner of Summerville with access from Exit 199, leading southeast to Charleston and northwest 90 miles (140 km) to Columbia.
According to the United States Census Bureau, the town has a total area of 18.1 square miles (47.0 km2), of which 18.0 square miles (46.7 km2) is land and 0.12 square miles (0.3 km2), or 0.62%, is water.
As of the census of 2010, there were 43,392 people residing in 16,181 households in the town.