Southern side of the Sunbury Town Hall, located on the village square at the center of Sunbury, Ohio, United States. Built in 1868, it is listed on the National Register of Historic Places. – Nyttend, Public domain – Wikimedia Commons Sunbury is located in Delaware County. About 6,614 people live here (as of 2020). Between 2010 and 2020, the population grew from 4,389 to 6,614. The region is at 296 meters above sea level. The area covers about 8.5 square kilometers. There are about 212 streets in Sunbury. The postal codes are 43074. Sunbury is city in Delaware County, Ohio, United States. Among other things, Sunbury has hotels, restaurants, cafés and hairdressers.