Hillandale is an unincorporated place located in the U.S. state of Maryland. It is within Montgomery County following to the border of Prince George's County. It has a total area of 2.0 square miles at 39°1′30″N 76°58′50″W. The elevation is 262 feet above sea level. As of the 2010 census data, it had a total population of 6,043. The population density was 3,000/sq mi. Estimated per capita income in 2016 was $39,145. It has Zip code 20903.