| | Roslyn, NY | Medford, NY | United States |
| Population | 2,971 | 24,702 | 329,725,481 |
| Female Population | 57.9% | 51.3% | 50.5% |
| Male Population | 42.1% | 48.7% | 49.5% |
| Median Age | 54.2 | 42.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,790 | 24,638 | 309,327,143 |
| Population - 2000 | 2,570 | 21,985 | 285,036,114 |
| Population - 1990 | 1,965 | 21,274 | 251,960,433 |
| Pop. 2000 to Now | 13.4% | 8.5% | 15.6% |
| Pop. 1990 to Now | 48.4% | 12.1% | 30.8% |
| space4 | | | |
| Population Density | 4,599.1 | 2,287.4 | 93.4 |
| Land Area | 0.6 | 10.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Roslyn, NY | Medford, NY | United States |
| Age 0 to 4 | 2.1% | 3.7% | 5.9% |
| Age 5 to 9 | 2.4% | 6.5% | 6.1% |
| Age 10 to 14 | 4.4% | 6.1% | 6.6% |
| Age 15 to 17 | 2.9% | 4.0% | 3.9% |
| Age 18 to 20 | 0.5% | 4.0% | 4.0% |
| Age 21 to 24 | 3.7% | 4.4% | 5.2% |
| Age 25 to 34 | 14.3% | 13.1% | 13.8% |
| Age 35 to 44 | 7.9% | 12.3% | 12.9% |
| Age 45 to 54 | 13.4% | 12.4% | 12.6% |
| Age 55 to 59 | 9.1% | 7.1% | 6.7% |
| Age 60 to 64 | 8.9% | 6.3% | 6.3% |
| Age 65 to 74 | 12.4% | 11.9% | 9.6% |
| Age 75 to 84 | 5.4% | 6.6% | 4.5% |
| Age 85 and over | 12.7% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Roslyn, NY | Medford, NY | United States |
| White | 67.9% | 61.4% | 59.4% |
| Black | 1.6% | 6.3% | 12.2% |
| Asian | 17.2% | 2.6% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 4.5% | 0.3% | 0.4% |
| Two or More Races | 0.2% | 1.5% | 3.2% |
| Hispanic | 8.5% | 27.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Roslyn, NY | Medford, NY | United States |
| Married Population | 46.5% | 51.0% | 49.8% |
| Currently Married | 43.0% | 49.8% | 48.0% |
| Married but Separated | 3.5% | 1.2% | 1.8% |
| Single Population | 53.5% | 49.0% | 50.2% |
| Never Married | 30.3% | 35.4% | 33.8% |
| Divorced | 11.4% | 7.2% | 10.8% |
| Widowed | 11.7% | 6.5% | 5.6% |
| space5 | | | |
| Household Size | 1.89 | 3.02 | 2.60 |
| Households | 1,452 | 8,061 | 124,010,992 |
| Family Households | 646 | 5,658 | 80,755,759 |
| Married couple, w/children | 26.9% | 34.8% | 30.5% |
| Married couple, no children | 57.7% | 48.0% | 42.9% |
| Non Family Households | 806 | 2,403 | 43,255,233 |
| Single householder, w/children | 8.8% | 7.3% | 15.8% |
| Single householder, no children | 6.5% | 9.8% | 10.8% |