There are 3 US Post Offices in Grady County serving a total of 18,580 residents equating to 6,193 residents per post office. It's estimated that approximately 29,656 packages are handled across the 3 county post offices annually. Grady County is a county located in the U.S. state of Georgia. As of the 2010 census, the population was 25,011. The county seat is Cairo."