| | St. Martin, MS | Flowood, MS | United States |
| Population | 7,984 | 10,019 | 329,725,481 |
| Female Population | 54.1% | 55.5% | 50.5% |
| Male Population | 45.9% | 44.6% | 49.5% |
| Median Age | 37.2 | 35.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,675 | 7,871 | 309,327,143 |
| Population - 2000 | 6,676 | 4,750 | 285,036,114 |
| Population - 1990 | 6,349 | 2,860 | 251,960,433 |
| Pop. 2000 to Now | 25.5% | 101.2% | 15.6% |
| Pop. 1990 to Now | 32.0% | 234.1% | 30.8% |
| space4 | | | |
| Population Density | 1,877.3 | 347.7 | 93.4 |
| Land Area | 4.3 | 28.8 | 3,531,905.4 |
| Water Area | 0.9 | 0.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | St. Martin, MS | Flowood, MS | United States |
| Age 0 to 4 | 4.8% | 7.0% | 5.9% |
| Age 5 to 9 | 3.9% | 8.8% | 6.1% |
| Age 10 to 14 | 6.6% | 4.9% | 6.6% |
| Age 15 to 17 | 5.2% | 3.2% | 3.9% |
| Age 18 to 20 | 2.3% | 1.0% | 4.0% |
| Age 21 to 24 | 7.4% | 7.0% | 5.2% |
| Age 25 to 34 | 16.1% | 17.8% | 13.8% |
| Age 35 to 44 | 14.5% | 14.6% | 12.9% |
| Age 45 to 54 | 13.1% | 15.6% | 12.6% |
| Age 55 to 59 | 10.2% | 6.2% | 6.7% |
| Age 60 to 64 | 3.5% | 5.2% | 6.3% |
| Age 65 to 74 | 7.0% | 6.3% | 9.6% |
| Age 75 to 84 | 4.3% | 1.4% | 4.5% |
| Age 85 and over | 1.1% | 1.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | St. Martin, MS | Flowood, MS | United States |
| White | 78.6% | 59.2% | 59.4% |
| Black | 12.5% | 28.9% | 12.2% |
| Asian | 3.4% | 6.2% | 5.6% |
| Native American | 0.1% | 0.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.6% | 1.5% | 3.2% |
| Hispanic | 2.9% | 3.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | St. Martin, MS | Flowood, MS | United States |
| Married Population | 39.8% | 57.6% | 49.8% |
| Currently Married | 38.6% | 54.8% | 48.0% |
| Married but Separated | 1.2% | 2.7% | 1.8% |
| Single Population | 60.2% | 42.4% | 50.2% |
| Never Married | 43.3% | 28.0% | 33.8% |
| Divorced | 9.4% | 10.7% | 10.8% |
| Widowed | 7.4% | 3.8% | 5.6% |
| space5 | | | |
| Household Size | 2.77 | 2.35 | 2.60 |
| Households | 2,883 | 4,178 | 124,010,992 |
| Family Households | 1,525 | 2,724 | 80,755,759 |
| Married couple, w/children | 35.3% | 33.4% | 30.5% |
| Married couple, no children | 39.7% | 40.7% | 42.9% |
| Non Family Households | 1,358 | 1,454 | 43,255,233 |
| Single householder, w/children | 16.1% | 15.7% | 15.8% |
| Single householder, no children | 8.8% | 10.1% | 10.8% |