There are 8 US Post Offices in Clayton County serving a total of 176,040 residents equating to 22,005 residents per post office. It's estimated that approximately 280,979 packages are handled across the 8 county post offices annually. Clayton County is a county located in the north central portion of the U.S. state of Georgia. As of the 2010 census, the population was 259,424. The county seat is Jonesboro. Clayton County is included in the Atlanta-Sandy Springs-Roswell, GA Metropolitan Statistical Area. It is the home of Hartsfield-Jackson Atlanta International Airport."