Bellefontaine is a city in, and the county seat of, Logan County, Ohio, United States, located 48 miles northwest of Columbus. The populati…Bellefontaine is a city in, and the county seat of, Logan County, Ohio, United States, located 48 miles northwest of Columbus. The population was 14,115 at the 2020 census. It is the principal city of the Bellefontaine micropolitan area, which includes all of Logan County. The highest point in Ohio, Campbell Hill, is within the city limits.