Resident Population in Chester County, PA was 549.78400 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Chester County, PA reached a record high of 549.78400 in January of 2023 and a record low of 277.74600 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Chester County, PA - last updated from the United States Federal Reserve on May of 2024.