| | Tecumseh, OK | Seminole, OK | United States |
| Population | 6,356 | 7,131 | 329,725,481 |
| Female Population | 50.3% | 55.5% | 50.5% |
| Male Population | 49.7% | 44.5% | 49.5% |
| Median Age | 34.9 | 33.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,493 | 7,474 | 309,327,143 |
| Population - 2000 | 6,098 | 6,899 | 285,036,114 |
| Population - 1990 | 5,750 | 7,071 | 251,960,433 |
| Pop. 2000 to Now | 8.9% | 2.0% | 15.6% |
| Pop. 1990 to Now | 15.5% | -0.5% | 30.8% |
| space4 | | | |
| Population Density | 423.4 | 525.5 | 93.4 |
| Land Area | 15.0 | 13.6 | 3,531,905.4 |
| Water Area | 0.2 | 0.6 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Tecumseh, OK | Seminole, OK | United States |
| Age 0 to 4 | 4.5% | 7.7% | 5.9% |
| Age 5 to 9 | 7.8% | 7.5% | 6.1% |
| Age 10 to 14 | 8.4% | 6.6% | 6.6% |
| Age 15 to 17 | 6.5% | 4.5% | 3.9% |
| Age 18 to 20 | 6.3% | 6.2% | 4.0% |
| Age 21 to 24 | 4.5% | 5.0% | 5.2% |
| Age 25 to 34 | 12.1% | 15.0% | 13.8% |
| Age 35 to 44 | 13.3% | 10.3% | 12.9% |
| Age 45 to 54 | 9.9% | 12.0% | 12.6% |
| Age 55 to 59 | 4.8% | 6.3% | 6.7% |
| Age 60 to 64 | 5.3% | 4.3% | 6.3% |
| Age 65 to 74 | 9.9% | 7.0% | 9.6% |
| Age 75 to 84 | 4.5% | 5.2% | 4.5% |
| Age 85 and over | 2.2% | 2.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Tecumseh, OK | Seminole, OK | United States |
| White | 68.9% | 59.1% | 59.4% |
| Black | 1.4% | 4.2% | 12.2% |
| Asian | 0.4% | 0.4% | 5.6% |
| Native American | 16.2% | 22.6% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 6.9% | 6.8% | 3.2% |
| Hispanic | 6.1% | 6.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Tecumseh, OK | Seminole, OK | United States |
| Married Population | 42.6% | 40.5% | 49.8% |
| Currently Married | 40.8% | 38.4% | 48.0% |
| Married but Separated | 1.8% | 2.2% | 1.8% |
| Single Population | 57.4% | 59.5% | 50.2% |
| Never Married | 31.4% | 32.7% | 33.8% |
| Divorced | 19.8% | 15.2% | 10.8% |
| Widowed | 6.2% | 11.6% | 5.6% |
| space5 | | | |
| Household Size | 2.79 | 2.85 | 2.60 |
| Households | 2,238 | 2,393 | 124,010,992 |
| Family Households | 1,577 | 1,622 | 80,755,759 |
| Married couple, w/children | 29.3% | 30.1% | 30.5% |
| Married couple, no children | 32.7% | 25.7% | 42.9% |
| Non Family Households | 661 | 771 | 43,255,233 |
| Single householder, w/children | 26.7% | 27.1% | 15.8% |
| Single householder, no children | 11.4% | 17.1% | 10.8% |