Marion is a city located in north-central Ohio within Marion County. It serves as the county seat and is the largest city in its county. Geographically, it is situated approximately 50 miles (80 km) north of Columbus.
The city functions as the principal city of the Marion micropolitan area and is included in the larger Columbus–Marion–Zanesville, OH Combined Statistical Area. According to the 2020 census, the population was 35,999, reflecting a slight decrease from the 36,837 residents recorded in 2010.