| | Marion, AL | Leeds, AL | United States |
| Population | 3,273 | 12,385 | 329,725,481 |
| Female Population | 59.3% | 48.2% | 50.5% |
| Male Population | 40.7% | 51.8% | 49.5% |
| Median Age | 30.6 | 38.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,675 | 11,793 | 309,327,143 |
| Population - 2000 | 3,511 | 10,455 | 285,036,114 |
| Population - 1990 | 4,211 | 9,946 | 251,960,433 |
| Pop. 2000 to Now | -13.2% | 15.0% | 15.6% |
| Pop. 1990 to Now | -27.6% | 20.9% | 30.8% |
| space4 | | | |
| Population Density | 309.8 | 550.9 | 93.4 |
| Land Area | 10.6 | 22.5 | 3,531,905.4 |
| Water Area | 0.1 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Marion, AL | Leeds, AL | United States |
| Age 0 to 4 | 4.6% | 5.8% | 5.9% |
| Age 5 to 9 | 7.3% | 6.4% | 6.1% |
| Age 10 to 14 | 7.1% | 7.4% | 6.6% |
| Age 15 to 17 | 2.5% | 6.3% | 3.9% |
| Age 18 to 20 | 14.6% | 2.6% | 4.0% |
| Age 21 to 24 | 6.8% | 1.9% | 5.2% |
| Age 25 to 34 | 10.8% | 14.5% | 13.8% |
| Age 35 to 44 | 7.4% | 12.8% | 12.9% |
| Age 45 to 54 | 7.8% | 13.5% | 12.6% |
| Age 55 to 59 | 6.4% | 5.9% | 6.7% |
| Age 60 to 64 | 1.7% | 7.2% | 6.3% |
| Age 65 to 74 | 16.5% | 9.7% | 9.6% |
| Age 75 to 84 | 4.5% | 5.0% | 4.5% |
| Age 85 and over | 2.1% | 1.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Marion, AL | Leeds, AL | United States |
| White | 35.9% | 80.5% | 59.4% |
| Black | 60.9% | 13.3% | 12.2% |
| Asian | 0.2% | 0.3% | 5.6% |
| Native American | 0.1% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.2% | 1.0% | 3.2% |
| Hispanic | 2.7% | 4.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Marion, AL | Leeds, AL | United States |
| Married Population | 23.4% | 54.2% | 49.8% |
| Currently Married | 22.7% | 52.6% | 48.0% |
| Married but Separated | 0.6% | 1.6% | 1.8% |
| Single Population | 76.6% | 45.8% | 50.2% |
| Never Married | 53.7% | 27.7% | 33.8% |
| Divorced | 7.2% | 11.7% | 10.8% |
| Widowed | 15.8% | 6.4% | 5.6% |
| space5 | | | |
| Household Size | 3.11 | 2.68 | 2.60 |
| Households | 794 | 4,620 | 124,010,992 |
| Family Households | 475 | 3,133 | 80,755,759 |
| Married couple, w/children | 13.3% | 33.9% | 30.5% |
| Married couple, no children | 22.3% | 43.3% | 42.9% |
| Non Family Households | 319 | 1,487 | 43,255,233 |
| Single householder, w/children | 29.3% | 12.6% | 15.8% |
| Single householder, no children | 35.2% | 10.2% | 10.8% |