There are 15 US Post Offices in Clermont County serving a total of 187,802 residents equating to 12,520 residents per post office. It's estimated that approximately 299,753 packages are handled across the 15 county post offices annually. Clermont County is a county located in the U.S. state of Ohio. As of the 2010 census, the population was 197,363. Its county seat is Batavia. The county is named for the Clermont Province of France and means \"clear mountain.\" Founded in 1800, it is Ohio's eighth oldest county and the state's furthest county west in Appalachia. Clermont County is part of the Cincinnati, OH-KY-IN Metropolitan Statistical Area."