Rockford is a village in Mercer County, Ohio, United States. The village is on the St. Mary's River near the center of the western Ohio border 12 miles Northwest of Celina. The population was 1,051 at the 2020 census.

Mercer County is located in the U.S. state of Ohio. As of the 2020 census, the population was 42,528. Its county seat is Celina. The county was created in 1820 and later organized in 1824. It is named for Hugh Mercer, an officer in the American Revolutionary War.