| | Dormont, PA | Oak Park, IL | United States |
| Population | 8,255 | 54,100 | 329,725,481 |
| Female Population | 47.3% | 53.0% | 50.5% |
| Male Population | 52.7% | 47.0% | 49.5% |
| Median Age | 37.1 | 39.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 8,601 | 51,896 | 309,327,143 |
| Population - 2000 | 9,305 | 52,524 | 285,036,114 |
| Population - 1990 | 9,772 | 53,648 | 251,960,433 |
| Pop. 2000 to Now | -11.6% | -1.3% | 15.6% |
| Pop. 1990 to Now | -15.8% | -3.4% | 30.8% |
| space4 | | | |
| Population Density | 10,861.8 | 11,510.6 | 93.4 |
| Land Area | 0.8 | 4.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Dormont, PA | Oak Park, IL | United States |
| Age 0 to 4 | 4.9% | 5.3% | 5.9% |
| Age 5 to 9 | 5.0% | 7.3% | 6.1% |
| Age 10 to 14 | 3.2% | 7.0% | 6.6% |
| Age 15 to 17 | 2.8% | 4.4% | 3.9% |
| Age 18 to 20 | 1.7% | 2.5% | 4.0% |
| Age 21 to 24 | 4.6% | 3.5% | 5.2% |
| Age 25 to 34 | 23.4% | 12.3% | 13.8% |
| Age 35 to 44 | 15.6% | 15.2% | 12.9% |
| Age 45 to 54 | 12.1% | 14.8% | 12.6% |
| Age 55 to 59 | 5.9% | 5.8% | 6.7% |
| Age 60 to 64 | 6.3% | 6.0% | 6.3% |
| Age 65 to 74 | 9.2% | 9.7% | 9.6% |
| Age 75 to 84 | 3.6% | 4.6% | 4.5% |
| Age 85 and over | 1.9% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Dormont, PA | Oak Park, IL | United States |
| White | 90.7% | 60.4% | 59.4% |
| Black | 2.1% | 18.2% | 12.2% |
| Asian | 1.1% | 5.3% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.2% | 0.6% | 0.4% |
| Two or More Races | 2.3% | 5.5% | 3.2% |
| Hispanic | 3.6% | 9.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Dormont, PA | Oak Park, IL | United States |
| Married Population | 40.7% | 49.8% | 49.8% |
| Currently Married | 39.5% | 49.1% | 48.0% |
| Married but Separated | 1.3% | 0.7% | 1.8% |
| Single Population | 59.3% | 50.2% | 50.2% |
| Never Married | 44.1% | 35.9% | 33.8% |
| Divorced | 10.5% | 9.6% | 10.8% |
| Widowed | 4.7% | 4.6% | 5.6% |
| space5 | | | |
| Household Size | 1.96 | 2.35 | 2.60 |
| Households | 4,189 | 22,793 | 124,010,992 |
| Family Households | 1,856 | 13,227 | 80,755,759 |
| Married couple, w/children | 25.9% | 38.8% | 30.5% |
| Married couple, no children | 49.4% | 38.4% | 42.9% |
| Non Family Households | 2,333 | 9,566 | 43,255,233 |
| Single householder, w/children | 13.0% | 13.6% | 15.8% |
| Single householder, no children | 11.8% | 9.2% | 10.8% |