There are 7 US Post Offices in Wyandot County serving a total of 23,909 residents equating to 3,416 residents per post office. It's estimated that approximately 38,161 packages are handled across the 7 county post offices annually. Wyandot County is a county located in the U.S. state of Ohio. As of the 2010 census, the population was 22,615. Its county seat is Upper Sandusky. Its name comes from the Wyandot Indians and is variously translated from their language as \"around the plains\" and \"dwellers on the peninsula\". It was formed from parts of Crawford, Marion, Hardin and Hancock Counties on February 3rd, 1845."