Lima is a city in and the county seat of Allen County, Ohio, United States. The municipality is located in northwestern Ohio along Interstate 75 approximately north of Dayton and south-southwest of Toledo.
As of the 2010 census, the city had a population of 38,771. It is the principal city of and is included in the Lima, Ohio Metropolitan Statistical Area, which is included in the Lima-Van Wert–Wapakoneta, Ohio, Combined Statistical Area. Lima was founded in 1831.