| | Ardsley, NY | Oceanside, NY | United States |
| Population | 4,984 | 31,182 | 329,725,481 |
| Female Population | 50.6% | 48.9% | 50.5% |
| Male Population | 49.4% | 51.1% | 49.5% |
| Median Age | 43.2 | 45.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 4,419 | 31,078 | 309,327,143 |
| Population - 2000 | 4,269 | 32,733 | 285,036,114 |
| Population - 1990 | 4,272 | 32,423 | 251,960,433 |
| Pop. 2000 to Now | 5.5% | -6.4% | 15.6% |
| Pop. 1990 to Now | 5.4% | -5.5% | 30.8% |
| space4 | | | |
| Population Density | 3,767.2 | 6,326.2 | 93.4 |
| Land Area | 1.3 | 4.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Ardsley, NY | Oceanside, NY | United States |
| Age 0 to 4 | 5.0% | 4.9% | 5.9% |
| Age 5 to 9 | 6.6% | 5.8% | 6.1% |
| Age 10 to 14 | 10.0% | 6.4% | 6.6% |
| Age 15 to 17 | 5.0% | 3.4% | 3.9% |
| Age 18 to 20 | 1.7% | 2.6% | 4.0% |
| Age 21 to 24 | 1.7% | 5.0% | 5.2% |
| Age 25 to 34 | 7.0% | 10.1% | 13.8% |
| Age 35 to 44 | 14.8% | 11.1% | 12.9% |
| Age 45 to 54 | 18.0% | 15.3% | 12.6% |
| Age 55 to 59 | 6.4% | 8.6% | 6.7% |
| Age 60 to 64 | 3.5% | 5.6% | 6.3% |
| Age 65 to 74 | 11.1% | 12.7% | 9.6% |
| Age 75 to 84 | 4.9% | 5.1% | 4.5% |
| Age 85 and over | 4.1% | 3.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Ardsley, NY | Oceanside, NY | United States |
| White | 67.3% | 77.9% | 59.4% |
| Black | 3.9% | 1.5% | 12.2% |
| Asian | 12.7% | 3.5% | 5.6% |
| Native American | 0.2% | 0.5% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.3% | 0.1% | 0.4% |
| Two or More Races | 9.8% | 1.1% | 3.2% |
| Hispanic | 5.8% | 15.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Ardsley, NY | Oceanside, NY | United States |
| Married Population | 69.6% | 61.2% | 49.8% |
| Currently Married | 69.6% | 59.7% | 48.0% |
| Married but Separated | 0.0% | 1.5% | 1.8% |
| Single Population | 30.4% | 38.8% | 50.2% |
| Never Married | 21.9% | 25.9% | 33.8% |
| Divorced | 3.6% | 5.8% | 10.8% |
| Widowed | 4.9% | 7.2% | 5.6% |
| space5 | | | |
| Household Size | 3.06 | 2.88 | 2.60 |
| Households | 1,628 | 10,781 | 124,010,992 |
| Family Households | 1,449 | 8,403 | 80,755,759 |
| Married couple, w/children | 48.0% | 34.9% | 30.5% |
| Married couple, no children | 42.0% | 49.3% | 42.9% |
| Non Family Households | 179 | 2,378 | 43,255,233 |
| Single householder, w/children | 4.8% | 5.9% | 15.8% |
| Single householder, no children | 5.3% | 9.8% | 10.8% |