There are 6 US Post Offices in Perry County serving a total of 23,707 residents equating to 3,951 residents per post office. It's estimated that approximately 37,839 packages are handled across the 6 county post offices annually. Perry County is a county located in the U.S. state of Illinois. According to the 2010 census, it had a population of 22,350. Its county seat is Pinckneyville. It is located in the southern portion of Illinois known locally as \"Little Egypt\"."