Upper Sandusky is a city and the county seat of Wyandot County, Ohio, United States, along the Sandusky River. The population was 6,596 at the 2010 census. The city takes its name from an earlier Wyandot Indian village of the same name, which was located nearby. Upper Sandusky is rich in history. Its origins date back to the early 1780s. It was home to the Wyandotte Native Americans until 1842. Upper Sandusky became the Wyandot County seat in 1843.