Joppatowne is an unincorporated "bedroom community" in southwestern Harford County, Maryland, United States. It was established in 1961 as a Planned Unit Development (PUD). Joppatowne is a census-designated place (CDP): the population was 11,391 at the 2000 census. Joppatowne is only a small part of what is currently described as the "Joppa" area of Harford County. Joppa is an area technically defined by the US postal zip code 21085, and a designated planning region for the county.