| | Onley, VA | Cape Charles, VA | United States |
| Population | 674 | 1,134 | 329,725,481 |
| Female Population | 50.9% | 58.2% | 50.5% |
| Male Population | 49.1% | 41.8% | 49.5% |
| Median Age | 40.5 | 56.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 516 | 1,011 | 309,327,143 |
| Population - 2000 | 496 | 1,134 | 285,036,114 |
| Population - 1990 | 532 | 1,398 | 251,960,433 |
| Pop. 2000 to Now | 0.6% | -6.9% | 15.6% |
| Pop. 1990 to Now | -6.2% | -24.5% | 30.8% |
| space4 | | | |
| Population Density | 842.5 | 319.2 | 93.4 |
| Land Area | 0.8 | 3.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Onley, VA | Cape Charles, VA | United States |
| Age 0 to 4 | 5.6% | 2.3% | 5.9% |
| Age 5 to 9 | 9.9% | 2.3% | 6.1% |
| Age 10 to 14 | 7.3% | 6.7% | 6.6% |
| Age 15 to 17 | 1.3% | 4.1% | 3.9% |
| Age 18 to 20 | 1.5% | 3.5% | 4.0% |
| Age 21 to 24 | 3.9% | 3.7% | 5.2% |
| Age 25 to 34 | 9.8% | 9.3% | 13.8% |
| Age 35 to 44 | 15.4% | 5.2% | 12.9% |
| Age 45 to 54 | 20.6% | 10.7% | 12.6% |
| Age 55 to 59 | 4.5% | 6.8% | 6.7% |
| Age 60 to 64 | 5.5% | 9.1% | 6.3% |
| Age 65 to 74 | 6.8% | 26.6% | 9.6% |
| Age 75 to 84 | 4.3% | 7.2% | 4.5% |
| Age 85 and over | 3.6% | 2.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Onley, VA | Cape Charles, VA | United States |
| White | 59.3% | 77.6% | 59.4% |
| Black | 8.2% | 13.7% | 12.2% |
| Asian | 0.9% | 0.8% | 5.6% |
| Native American | 4.9% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.4% | 3.2% | 3.2% |
| Hispanic | 26.3% | 4.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Onley, VA | Cape Charles, VA | United States |
| Married Population | 58.7% | 45.2% | 49.8% |
| Currently Married | 55.0% | 43.3% | 48.0% |
| Married but Separated | 3.7% | 1.9% | 1.8% |
| Single Population | 41.3% | 54.8% | 50.2% |
| Never Married | 18.5% | 27.1% | 33.8% |
| Divorced | 11.7% | 20.9% | 10.8% |
| Widowed | 11.2% | 6.8% | 5.6% |
| space5 | | | |
| Household Size | 2.29 | 1.94 | 2.60 |
| Households | 294 | 584 | 124,010,992 |
| Family Households | 181 | 277 | 80,755,759 |
| Married couple, w/children | 24.9% | 7.6% | 30.5% |
| Married couple, no children | 51.9% | 70.0% | 42.9% |
| Non Family Households | 113 | 307 | 43,255,233 |
| Single householder, w/children | 11.1% | 19.9% | 15.8% |
| Single householder, no children | 12.2% | 2.5% | 10.8% |