| | Okmulgee, OK | Ada, OK | United States |
| Population | 11,330 | 16,804 | 329,725,481 |
| Female Population | 51.7% | 52.8% | 50.5% |
| Male Population | 48.3% | 47.2% | 49.5% |
| Median Age | 35 | 31.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 12,496 | 16,833 | 309,327,143 |
| Population - 2000 | 13,022 | 15,691 | 285,036,114 |
| Population - 1990 | 13,441 | 15,820 | 251,960,433 |
| Pop. 2000 to Now | -10.8% | 9.9% | 15.6% |
| Pop. 1990 to Now | -13.6% | 9.0% | 30.8% |
| space4 | | | |
| Population Density | 663.1 | 850.8 | 93.4 |
| Land Area | 17.1 | 19.8 | 3,531,905.4 |
| Water Area | 2.8 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Okmulgee, OK | Ada, OK | United States |
| Age 0 to 4 | 5.6% | 6.6% | 5.9% |
| Age 5 to 9 | 5.6% | 6.8% | 6.1% |
| Age 10 to 14 | 6.3% | 6.5% | 6.6% |
| Age 15 to 17 | 3.7% | 3.4% | 3.9% |
| Age 18 to 20 | 7.2% | 7.9% | 4.0% |
| Age 21 to 24 | 6.4% | 7.9% | 5.2% |
| Age 25 to 34 | 15.0% | 16.0% | 13.8% |
| Age 35 to 44 | 9.8% | 11.8% | 12.9% |
| Age 45 to 54 | 11.6% | 10.5% | 12.6% |
| Age 55 to 59 | 5.5% | 4.2% | 6.7% |
| Age 60 to 64 | 7.7% | 4.8% | 6.3% |
| Age 65 to 74 | 8.3% | 7.3% | 9.6% |
| Age 75 to 84 | 4.7% | 4.0% | 4.5% |
| Age 85 and over | 2.5% | 2.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Okmulgee, OK | Ada, OK | United States |
| White | 49.9% | 58.8% | 59.4% |
| Black | 17.3% | 4.9% | 12.2% |
| Asian | 1.3% | 1.9% | 5.6% |
| Native American | 16.8% | 17.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.4% | 0.2% |
| Other | 0.3% | 0.3% | 0.4% |
| Two or More Races | 11.3% | 11.3% | 3.2% |
| Hispanic | 3.1% | 5.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Okmulgee, OK | Ada, OK | United States |
| Married Population | 35.7% | 38.8% | 49.8% |
| Currently Married | 32.5% | 36.5% | 48.0% |
| Married but Separated | 3.2% | 2.3% | 1.8% |
| Single Population | 64.3% | 61.2% | 50.2% |
| Never Married | 40.1% | 39.3% | 33.8% |
| Divorced | 15.6% | 14.6% | 10.8% |
| Widowed | 8.6% | 7.4% | 5.6% |
| space5 | | | |
| Household Size | 2.37 | 2.36 | 2.60 |
| Households | 4,324 | 6,619 | 124,010,992 |
| Family Households | 2,548 | 3,677 | 80,755,759 |
| Married couple, w/children | 18.3% | 27.6% | 30.5% |
| Married couple, no children | 31.3% | 33.8% | 42.9% |
| Non Family Households | 1,776 | 2,942 | 43,255,233 |
| Single householder, w/children | 29.6% | 23.0% | 15.8% |
| Single householder, no children | 20.8% | 15.6% | 10.8% |