Cockeysville is a census-designated place located in the U.S. state of Maryland. It is within Baltimore County. It has a total area of 11.5 square miles at 39°28′24″N 76°37′36″W. The elevation is 308 feet above sea level. As of the 2010 census data, it had a total population of 20,776. The population density was 1,800/sq mi. It has Zip codes 21030, 21031, and 210652.