Harbeson is an unincorporated community in east central Sussex County, Delaware, United States. It lies at the intersection of U.S. Route 9/Delaware Route 404 and Delaware Route 5, east of the town of Georgetown, the county seat of Sussex County. Its elevation is 36 feet. Although it is unincorporated, it has a post office, with the ZIP code of 19951.Harbeson is part of the Salisbury, Maryland-Delaware Metropolitan Statistical Area.Harbeson was named for Harbeson Hickman, a large landowner.