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 (PUD). The population was 12,616 at the 2010 census, up from 11,391 at the 2000 census.
Joppatowne is covered by the "Joppa" ZIP Code of 21085, and "Joppa" is a designated planning region for Harford County. The Joppa ZIP code (21085) extends 6 miles (10 km) north of Joppatowne, as far as Benson, just south of Bel Air.
The namesake of both Joppatowne and Joppa is the original town of "Joppa". It was a major seaport in American colonial times and the county seat of the original Baltimore County until 1768. Its site is located within the boundaries of present-day Joppatowne.