Stone Mountain is a city in DeKalb County, Georgia, United States. The population was 5,802 according to the 2010 US Census . Stone Mountain is located in the eastern part of DeKalb County and is a suburb of Atlanta that encompasses nearly 1.7 square miles. It lies near and touches the western base of the geological formation Stone Mountain. Locals often refer to the city as Stone Mountain Village to distinguish it from the larger unincorporated area traditionally considered Stone Mountain and Stone Mountain Park.