There are 17 US Post Offices in Aiken County serving a total of 134,474 residents equating to 7,910 residents per post office. It's estimated that approximately 214,636 packages are handled across the 17 county post offices annually. Aiken County /\u02c8e\u026ak\u0259n/ is a county located in the U.S. state of South Carolina. As of the 2010 U.S. Census, its population was 160,099. Its county seat and largest city is Aiken. Aiken County is a part of the Augusta-Richmond County, GA-SC Metropolitan Statistical Area. It is located in the Piedmont region."