| | Seagoville, TX | Forney, TX | United States |
| Population | 18,263 | 22,770 | 329,725,481 |
| Female Population | 43.7% | 47.4% | 50.5% |
| Male Population | 56.3% | 52.6% | 49.5% |
| Median Age | 32.9 | 32.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 14,960 | 13,946 | 309,327,143 |
| Population - 2000 | 10,823 | 5,588 | 285,036,114 |
| Population - 1990 | 8,969 | 4,070 | 251,960,433 |
| Pop. 2000 to Now | 58.7% | 423.4% | 15.6% |
| Pop. 1990 to Now | 91.5% | 618.6% | 30.8% |
| space4 | | | |
| Population Density | 969.0 | 1,538.8 | 93.4 |
| Land Area | 18.8 | 14.8 | 3,531,905.4 |
| Water Area | 0.3 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Seagoville, TX | Forney, TX | United States |
| Age 0 to 4 | 8.6% | 9.2% | 5.9% |
| Age 5 to 9 | 6.4% | 7.7% | 6.1% |
| Age 10 to 14 | 9.0% | 6.2% | 6.6% |
| Age 15 to 17 | 5.6% | 4.9% | 3.9% |
| Age 18 to 20 | 3.8% | 4.7% | 4.0% |
| Age 21 to 24 | 5.6% | 5.7% | 5.2% |
| Age 25 to 34 | 14.1% | 17.0% | 13.8% |
| Age 35 to 44 | 17.5% | 15.3% | 12.9% |
| Age 45 to 54 | 11.2% | 12.2% | 12.6% |
| Age 55 to 59 | 3.2% | 5.0% | 6.7% |
| Age 60 to 64 | 3.9% | 4.1% | 6.3% |
| Age 65 to 74 | 7.7% | 5.4% | 9.6% |
| Age 75 to 84 | 2.6% | 2.0% | 4.5% |
| Age 85 and over | 0.8% | 0.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Seagoville, TX | Forney, TX | United States |
| White | 26.3% | 62.2% | 59.4% |
| Black | 14.2% | 15.6% | 12.2% |
| Asian | 0.5% | 2.0% | 5.6% |
| Native American | 0.7% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 1.9% | 1.8% | 3.2% |
| Hispanic | 56.3% | 18.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Seagoville, TX | Forney, TX | United States |
| Married Population | 38.8% | 56.1% | 49.8% |
| Currently Married | 37.0% | 56.0% | 48.0% |
| Married but Separated | 1.8% | 0.1% | 1.8% |
| Single Population | 61.2% | 43.9% | 50.2% |
| Never Married | 41.8% | 28.6% | 33.8% |
| Divorced | 14.8% | 12.2% | 10.8% |
| Widowed | 4.6% | 3.1% | 5.6% |
| space5 | | | |
| Household Size | 3.29 | 2.90 | 2.60 |
| Households | 4,967 | 7,860 | 124,010,992 |
| Family Households | 3,747 | 5,931 | 80,755,759 |
| Married couple, w/children | 30.5% | 46.3% | 30.5% |
| Married couple, no children | 26.4% | 31.3% | 42.9% |
| Non Family Households | 1,220 | 1,929 | 43,255,233 |
| Single householder, w/children | 33.2% | 17.7% | 15.8% |
| Single householder, no children | 9.9% | 4.7% | 10.8% |