Logan County is a county in the west central portion of the U.S. state of Ohio. As of the 2020 census, the population was 46,150. The county seat is Bellefontaine. The county is named for Benjamin Logan, who fought Native Americans in the area. Logan County comprises the Bellefontaine, Ohio Micropolitan Statistical Area, which is also included in the Columbus-Marion-Zanesville, Ohio Combined Statistical Area.