| | Hattiesburg, MS | Spanish Fort, AL | United States |
| Population | 47,074 | 9,720 | 329,725,481 |
| Female Population | 53.7% | 50.9% | 50.5% |
| Male Population | 46.3% | 49.1% | 49.5% |
| Median Age | 29.6 | 36.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 45,782 | 6,892 | 309,327,143 |
| Population - 2000 | 44,779 | 5,423 | 285,036,114 |
| Population - 1990 | 41,882 | 3,732 | 251,960,433 |
| Pop. 2000 to Now | 2.3% | 74.4% | 15.6% |
| Pop. 1990 to Now | 9.4% | 153.5% | 30.8% |
| space4 | | | |
| Population Density | 881.0 | 321.6 | 93.4 |
| Land Area | 53.4 | 30.2 | 3,531,905.4 |
| Water Area | 1.0 | 4.7 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Hattiesburg, MS | Spanish Fort, AL | United States |
| Age 0 to 4 | 6.7% | 7.6% | 5.9% |
| Age 5 to 9 | 5.3% | 8.9% | 6.1% |
| Age 10 to 14 | 5.8% | 7.1% | 6.6% |
| Age 15 to 17 | 2.8% | 3.6% | 3.9% |
| Age 18 to 20 | 7.8% | 6.1% | 4.0% |
| Age 21 to 24 | 11.6% | 4.9% | 5.2% |
| Age 25 to 34 | 18.9% | 10.5% | 13.8% |
| Age 35 to 44 | 10.2% | 10.3% | 12.9% |
| Age 45 to 54 | 8.3% | 14.2% | 12.6% |
| Age 55 to 59 | 4.5% | 8.2% | 6.7% |
| Age 60 to 64 | 4.9% | 3.8% | 6.3% |
| Age 65 to 74 | 7.0% | 8.2% | 9.6% |
| Age 75 to 84 | 4.3% | 4.9% | 4.5% |
| Age 85 and over | 1.8% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Hattiesburg, MS | Spanish Fort, AL | United States |
| White | 37.3% | 78.2% | 59.4% |
| Black | 54.4% | 7.8% | 12.2% |
| Asian | 0.9% | 0.9% | 5.6% |
| Native American | 0.2% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 3.2% | 10.2% | 3.2% |
| Hispanic | 3.7% | 2.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Hattiesburg, MS | Spanish Fort, AL | United States |
| Married Population | 30.8% | 52.2% | 49.8% |
| Currently Married | 28.2% | 51.7% | 48.0% |
| Married but Separated | 2.6% | 0.5% | 1.8% |
| Single Population | 69.2% | 47.8% | 50.2% |
| Never Married | 52.8% | 25.7% | 33.8% |
| Divorced | 11.2% | 11.4% | 10.8% |
| Widowed | 5.1% | 10.8% | 5.6% |
| space5 | | | |
| Household Size | 2.36 | 2.73 | 2.60 |
| Households | 18,594 | 3,556 | 124,010,992 |
| Family Households | 9,785 | 2,178 | 80,755,759 |
| Married couple, w/children | 21.7% | 47.9% | 30.5% |
| Married couple, no children | 31.1% | 37.9% | 42.9% |
| Non Family Households | 8,809 | 1,378 | 43,255,233 |
| Single householder, w/children | 29.7% | 11.7% | 15.8% |
| Single householder, no children | 17.5% | 2.5% | 10.8% |