Dayton is a town in York County, Maine, United States; the town is located near the Saco-Biddeford city area. Dayton borders Biddeford by land, and borders Saco on the Saco River. It is also part of the Portland–South Portland–Biddeford, Maine metropolitan statistical area. The population was 2,129 at the 2020 census. Dayton is one of the smallest towns i…Dayton is a town in York County, Maine, United States; the town is located near the Saco-Biddeford city area. Dayton borders Biddeford by land, and borders Saco on the Saco River. It is also part of the Portland–South Portland–Biddeford, Maine metropolitan statistical area. The population was 2,129 at the 2020 census. Dayton is one of the smallest towns in York County.