| | Fairburn, GA | Austell, GA | United States |
| Population | 16,215 | 8,194 | 329,725,481 |
| Female Population | 54.7% | 52.4% | 50.5% |
| Male Population | 45.3% | 47.6% | 49.5% |
| Median Age | 29.9 | 33.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 13,165 | 6,530 | 309,327,143 |
| Population - 2000 | 5,464 | 5,359 | 285,036,114 |
| Population - 1990 | 4,013 | 4,173 | 251,960,433 |
| Pop. 2000 to Now | 213.6% | 34.5% | 15.6% |
| Pop. 1990 to Now | 327.0% | 72.7% | 30.8% |
| space4 | | | |
| Population Density | 958.6 | 1,364.1 | 93.4 |
| Land Area | 16.9 | 6.0 | 3,531,905.4 |
| Water Area | 0.2 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Fairburn, GA | Austell, GA | United States |
| Age 0 to 4 | 16.0% | 4.6% | 5.9% |
| Age 5 to 9 | 8.1% | 11.3% | 6.1% |
| Age 10 to 14 | 8.5% | 7.8% | 6.6% |
| Age 15 to 17 | 3.9% | 5.2% | 3.9% |
| Age 18 to 20 | 3.6% | 2.7% | 4.0% |
| Age 21 to 24 | 2.3% | 4.5% | 5.2% |
| Age 25 to 34 | 16.2% | 16.0% | 13.8% |
| Age 35 to 44 | 14.6% | 12.0% | 12.9% |
| Age 45 to 54 | 11.4% | 19.8% | 12.6% |
| Age 55 to 59 | 4.5% | 4.9% | 6.7% |
| Age 60 to 64 | 4.3% | 3.0% | 6.3% |
| Age 65 to 74 | 4.6% | 6.5% | 9.6% |
| Age 75 to 84 | 1.4% | 0.9% | 4.5% |
| Age 85 and over | 0.5% | 0.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Fairburn, GA | Austell, GA | United States |
| White | 10.3% | 25.1% | 59.4% |
| Black | 69.3% | 61.6% | 12.2% |
| Asian | 0.5% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.4% | 0.2% | 0.4% |
| Two or More Races | 2.2% | 5.1% | 3.2% |
| Hispanic | 17.3% | 8.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Fairburn, GA | Austell, GA | United States |
| Married Population | 30.9% | 44.2% | 49.8% |
| Currently Married | 29.8% | 40.5% | 48.0% |
| Married but Separated | 1.1% | 3.7% | 1.8% |
| Single Population | 69.1% | 55.8% | 50.2% |
| Never Married | 46.8% | 40.4% | 33.8% |
| Divorced | 17.7% | 10.2% | 10.8% |
| Widowed | 4.5% | 5.2% | 5.6% |
| space5 | | | |
| Household Size | 2.86 | 2.92 | 2.60 |
| Households | 5,642 | 2,802 | 124,010,992 |
| Family Households | 3,657 | 2,105 | 80,755,759 |
| Married couple, w/children | 28.0% | 25.7% | 30.5% |
| Married couple, no children | 15.2% | 25.5% | 42.9% |
| Non Family Households | 1,985 | 697 | 43,255,233 |
| Single householder, w/children | 35.3% | 33.4% | 15.8% |
| Single householder, no children | 21.4% | 15.4% | 10.8% |