| | Allison Park, PA | McKees Rocks, PA | United States |
| Population | 23,160 | 5,930 | 329,725,481 |
| Female Population | 51.2% | 49.2% | 50.5% |
| Male Population | 48.8% | 50.8% | 49.5% |
| Median Age | 43.9 | 42.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 22,293 | 6,083 | 309,327,143 |
| Population - 2000 | 20,847 | 6,622 | 285,036,114 |
| Population - 1990 | 20,294 | 7,691 | 251,960,433 |
| Pop. 2000 to Now | 4.2% | -12.2% | 15.6% |
| Pop. 1990 to Now | 7.0% | -24.4% | 30.8% |
| space4 | | | |
| Population Density | 1,672.9 | 5,610.2 | 93.4 |
| Land Area | 13.8 | 1.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Allison Park, PA | McKees Rocks, PA | United States |
| Age 0 to 4 | 6.2% | 5.5% | 5.9% |
| Age 5 to 9 | 4.3% | 6.2% | 6.1% |
| Age 10 to 14 | 6.3% | 5.6% | 6.6% |
| Age 15 to 17 | 3.5% | 3.9% | 3.9% |
| Age 18 to 20 | 3.9% | 2.9% | 4.0% |
| Age 21 to 24 | 3.6% | 3.7% | 5.2% |
| Age 25 to 34 | 12.4% | 15.7% | 13.8% |
| Age 35 to 44 | 12.2% | 9.8% | 12.9% |
| Age 45 to 54 | 13.1% | 11.0% | 12.6% |
| Age 55 to 59 | 7.4% | 11.4% | 6.7% |
| Age 60 to 64 | 7.5% | 7.9% | 6.3% |
| Age 65 to 74 | 11.5% | 9.6% | 9.6% |
| Age 75 to 84 | 5.7% | 3.2% | 4.5% |
| Age 85 and over | 2.3% | 3.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Allison Park, PA | McKees Rocks, PA | United States |
| White | 89.5% | 51.1% | 59.4% |
| Black | 2.9% | 28.0% | 12.2% |
| Asian | 3.3% | 3.9% | 5.6% |
| Native American | 0.0% | 1.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 5.1% | 0.4% |
| Two or More Races | 2.1% | 6.8% | 3.2% |
| Hispanic | 2.1% | 4.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Allison Park, PA | McKees Rocks, PA | United States |
| Married Population | 59.9% | 21.5% | 49.8% |
| Currently Married | 58.2% | 18.8% | 48.0% |
| Married but Separated | 1.8% | 2.7% | 1.8% |
| Single Population | 40.1% | 78.5% | 50.2% |
| Never Married | 28.8% | 55.9% | 33.8% |
| Divorced | 6.5% | 15.9% | 10.8% |
| Widowed | 4.7% | 6.7% | 5.6% |
| space5 | | | |
| Household Size | 2.41 | 2.08 | 2.60 |
| Households | 9,350 | 2,838 | 124,010,992 |
| Family Households | 6,222 | 1,161 | 80,755,759 |
| Married couple, w/children | 33.6% | 13.2% | 30.5% |
| Married couple, no children | 52.7% | 18.8% | 42.9% |
| Non Family Households | 3,128 | 1,677 | 43,255,233 |
| Single householder, w/children | 8.1% | 36.3% | 15.8% |
| Single householder, no children | 5.6% | 31.8% | 10.8% |