Ontario is a city in Richland County in the U.S. state of Ohio. It was founded in 1834 on the western edge of the Allegheny Plateau, just west of the city of Mansfield. The city's industry has since diversified into the service economy, including education, finance and healthcare. The city is also a major regional retail hub serving the entire North-Central Ohio area, with a shopping population of over 150,000. As of the 2010 Census, the city had a population of 6,225. It is part of the Mansfield, Ohio Metropolitan Statistical Area.
