Stone Mountain, GA has a population of 6,102 and is the 5,698th largest city in the United States. The population density is 3,720 per sq mi which is 2128% higher than the Georgia average and 4006% higher than the national average. The median age in Stone Mountain is 40 which is approximately 11% higher than the Georgia average of 36. In Stone Mountain, 39% of the population over 15 years of age are married, 92% speak English and 3% speak Spanish. 49% of Stone Mountain residents were born in Georgia, 41% were born out of state, 1% were born outside of the United States and 9% were foreign born.