There are 6 US Post Offices in Chester County serving a total of 33,590 residents equating to 5,598 residents per post office. It's estimated that approximately 53,613 packages are handled across the 6 county post offices annually. Chester County is a county located in the U.S. state of South Carolina. As of the 2010 census, its population was 33,140. Its county seat is Chester. Chester County is included in the Charlotte-Concord-Gastonia, NC-SC Metropolitan Statistical Area."