Greenfield is a small village in Highland, Fayette 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 Ron Coffee, who was born and raised in Greenfield.