New Philadelphia is a city in and the county seat of Tuscarawas County, Ohio, United States. The county's largest city, New Philadelphia lies along the Tuscarawas River. The population was 17,677 at the 2020 census. It is a principal city in the New Philadelphia–Dover micropolitan area, approximately 70 miles south of Cleveland. In 1772, the Moravian Christians founded the community of Schoenbrunn in the area, which was the first settlement of the Northwest Territory.