Greenfield is a large village in Highland and Ross counties, Ohio, United States. As of the 2010 census, the population was 4,639. Since the population declined to under 5,000, the Census Bureau may still call it a city, but by Ohio's laws it is technically deemed a village. Since the change from city to village there is no longer a mayor of the town but a city manager; the current city manager is Todd Wilkin. Greenfield is most well known because of its rich history, including its community members helping in the underground railroad, new industries, and a school.