Aerial view of De Graff, Ohio, United States, taken from Diamond Eclipse light airplane. Picture taken from an altitude of 2,350 feet MSL at an bearing of approximately 342º. – Nyttend, Public domain – Wikimedia Commons De Graff is located in Logan County. About 1,250 people live here (as of 2020). Between 2010 and 2020, the population declined from 1,285 to 1,250. The region is at 305 meters above sea level. The area covers about 2.6 square kilometers. There are about 53 streets in De Graff. The postal codes are 43318. De Graff is village in Ohio.