Vermilion is a city in Erie and Lorain Counties in the U.S. state of Ohio, on Lake Erie. Its population was 10,659 at the 2020 census. Located ab…Vermilion is a city in Erie and Lorain Counties in the U.S. state of Ohio, on Lake Erie. Its population was 10,659 at the 2020 census. Located about 35 miles west of Cleveland and 17 miles east of Sandusky, it is part of the Cleveland metropolitan area and Sandusky micropolitan area.