There are 4 US Post Offices in Mason County serving a total of 17,073 residents equating to 4,268 residents per post office. It's estimated that approximately 27,250 packages are handled across the 4 county post offices annually. Mason County is a county located in the U.S. state of Kentucky. As of the 2010 census, the population was 17,490. Its county seat is Maysville. The county was created from Bourbon County, Virginia in 1788 and named for George Mason, a Virginia delegate to the U.S. Constitutional Convention, known as the \"Father of the Bill of Rights\". Mason County comprises the Maysville, KY Micropolitan Statistical Area, which is included in the Cincinnati-Wilmington-Maysville, OH-KY-IN Combined Statistical Area."