Berwyn (after the Berwyn mountain range in north-east Wales) is a census-designated place (CDP) in Chester County, Pennsylvania, United States. The population was 3,631 at the 2010 census. Prior to 2010 it was part of the Devon-Berwyn CDP. The area is part of Philadelphia’s Main Line suburbs. At times, the village has been called Cocheltown, Reeseville, Glassley and Gaysville. The town received its present name in 1877 during the celebration of its centennial when one of the Welsh settlers proposed to name the village after the Berwyn Hills overlooking the Valley of the Dee River in Merionedd, Wales. Berwyn is located within Tredyffrin and Easttown Townships.