| | Athens, TN | Huntsville, AL | United States |
| Population | 13,961 | 210,081 | 329,725,481 |
| Female Population | 51.2% | 51.3% | 50.5% |
| Male Population | 48.8% | 48.7% | 49.5% |
| Median Age | 40 | 37.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 13,672 | 180,926 | 309,327,143 |
| Population - 2000 | 13,220 | 158,216 | 285,036,114 |
| Population - 1990 | 12,054 | 159,789 | 251,960,433 |
| Pop. 2000 to Now | 6.8% | 28.3% | 15.6% |
| Pop. 1990 to Now | 17.1% | 27.0% | 30.8% |
| space4 | | | |
| Population Density | 900.3 | 980.1 | 93.4 |
| Land Area | 15.5 | 214.4 | 3,531,905.4 |
| Water Area | 0.0 | 1.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Athens, TN | Huntsville, AL | United States |
| Age 0 to 4 | 5.8% | 5.8% | 5.9% |
| Age 5 to 9 | 4.1% | 5.7% | 6.1% |
| Age 10 to 14 | 4.9% | 5.4% | 6.6% |
| Age 15 to 17 | 3.8% | 2.9% | 3.9% |
| Age 18 to 20 | 5.5% | 4.8% | 4.0% |
| Age 21 to 24 | 6.0% | 7.1% | 5.2% |
| Age 25 to 34 | 14.8% | 15.5% | 13.8% |
| Age 35 to 44 | 13.3% | 12.1% | 12.9% |
| Age 45 to 54 | 13.1% | 11.5% | 12.6% |
| Age 55 to 59 | 6.6% | 6.8% | 6.7% |
| Age 60 to 64 | 5.4% | 6.2% | 6.3% |
| Age 65 to 74 | 9.7% | 9.3% | 9.6% |
| Age 75 to 84 | 3.9% | 4.8% | 4.5% |
| Age 85 and over | 3.1% | 2.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Athens, TN | Huntsville, AL | United States |
| White | 80.5% | 57.0% | 59.4% |
| Black | 8.1% | 30.6% | 12.2% |
| Asian | 1.1% | 2.2% | 5.6% |
| Native American | 0.3% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.2% | 0.1% | 0.4% |
| Two or More Races | 2.5% | 3.3% | 3.2% |
| Hispanic | 7.3% | 6.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Athens, TN | Huntsville, AL | United States |
| Married Population | 41.6% | 45.7% | 49.8% |
| Currently Married | 39.3% | 43.6% | 48.0% |
| Married but Separated | 2.3% | 2.1% | 1.8% |
| Single Population | 58.4% | 54.3% | 50.2% |
| Never Married | 31.2% | 36.1% | 33.8% |
| Divorced | 18.7% | 12.4% | 10.8% |
| Widowed | 8.5% | 5.9% | 5.6% |
| space5 | | | |
| Household Size | 2.25 | 2.21 | 2.60 |
| Households | 5,774 | 91,048 | 124,010,992 |
| Family Households | 3,361 | 51,704 | 80,755,759 |
| Married couple, w/children | 26.8% | 23.3% | 30.5% |
| Married couple, no children | 36.5% | 45.6% | 42.9% |
| Non Family Households | 2,413 | 39,344 | 43,255,233 |
| Single householder, w/children | 22.7% | 19.0% | 15.8% |
| Single householder, no children | 14.0% | 12.1% | 10.8% |