Berwyn is a suburban city in Cook County, Illinois, United States, coterminous with Berwyn Township, which was formed in 1908 after …Berwyn is a suburban city in Cook County, Illinois, United States, coterminous with Berwyn Township, which was formed in 1908 after breaking off from Cicero Township. As of the 2020 census, the city had a total population of 57,250. It is part of the Chicago metropolitan area.