Sullivan
Market InsightsSullivan is an unincorporated community in central Sullivan Township, Ashland County, Ohio, United States. Although it is unincorporated, it has a post office, with the ZIP code of 44880. It lies at the intersection of U.S. Route 224 with State Route 58.Sullivan was laid out in 1836. A post office called Sullivan has been in operation since 1828, which was closed in the summer of 2015.