Joppatowne is a census-designated place in southwestern Harford County, Maryland, United States. Serving as a bedroom community for nearby Baltimore, it was established in 1961 as a planned unit development. The population was 12,616 at the 2010 census, up from 11,391 in 2000. Joppatowne is covered by the "Joppa" ZIP Code of 21085, and "Joppa" is a designated planning region for Harford County. The Joppa ZIP code extends 6 miles north of Joppatowne, as far as Benson, just south of Bel Air.