| | Palmetto Bay, FL | Key Biscayne, FL | United States |
| Population | 24,327 | 14,530 | 329,725,481 |
| Female Population | 48.4% | 51.3% | 50.5% |
| Male Population | 51.6% | 48.7% | 49.5% |
| Median Age | 41.8 | 41.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 23,493 | 12,389 | 309,327,143 |
| Population - 2000 | 23,887 | 10,507 | 285,036,114 |
| Population - 1990 | 21,466 | 8,854 | 251,960,433 |
| Pop. 2000 to Now | 1.4% | 21.2% | 15.6% |
| Pop. 1990 to Now | 12.8% | 43.8% | 30.8% |
| space4 | | | |
| Population Density | 2,936.3 | 11,652.0 | 93.4 |
| Land Area | 8.3 | 1.2 | 3,531,905.4 |
| Water Area | 0.2 | 0.5 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Palmetto Bay, FL | Key Biscayne, FL | United States |
| Age 0 to 4 | 5.8% | 4.4% | 5.9% |
| Age 5 to 9 | 7.1% | 7.2% | 6.1% |
| Age 10 to 14 | 7.2% | 13.9% | 6.6% |
| Age 15 to 17 | 5.0% | 6.8% | 3.9% |
| Age 18 to 20 | 2.8% | 2.4% | 4.0% |
| Age 21 to 24 | 4.3% | 3.9% | 5.2% |
| Age 25 to 34 | 10.4% | 4.0% | 13.8% |
| Age 35 to 44 | 12.0% | 11.7% | 12.9% |
| Age 45 to 54 | 16.1% | 20.9% | 12.6% |
| Age 55 to 59 | 8.0% | 5.7% | 6.7% |
| Age 60 to 64 | 7.5% | 4.8% | 6.3% |
| Age 65 to 74 | 8.5% | 7.3% | 9.6% |
| Age 75 to 84 | 4.0% | 5.6% | 4.5% |
| Age 85 and over | 1.2% | 1.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Palmetto Bay, FL | Key Biscayne, FL | United States |
| White | 40.2% | 23.4% | 59.4% |
| Black | 2.6% | 0.3% | 12.2% |
| Asian | 4.4% | 0.2% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 1.0% | 0.0% | 0.4% |
| Two or More Races | 2.9% | 1.6% | 3.2% |
| Hispanic | 48.9% | 74.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Palmetto Bay, FL | Key Biscayne, FL | United States |
| Married Population | 61.5% | 59.0% | 49.8% |
| Currently Married | 60.2% | 58.7% | 48.0% |
| Married but Separated | 1.2% | 0.3% | 1.8% |
| Single Population | 38.5% | 41.0% | 50.2% |
| Never Married | 26.4% | 29.0% | 33.8% |
| Divorced | 8.8% | 7.5% | 10.8% |
| Widowed | 3.3% | 4.5% | 5.6% |
| space5 | | | |
| Household Size | 3.12 | 3.17 | 2.60 |
| Households | 7,799 | 4,580 | 124,010,992 |
| Family Households | 6,403 | 3,584 | 80,755,759 |
| Married couple, w/children | 40.7% | 52.9% | 30.5% |
| Married couple, no children | 43.4% | 32.8% | 42.9% |
| Non Family Households | 1,396 | 996 | 43,255,233 |
| Single householder, w/children | 7.7% | 8.6% | 15.8% |
| Single householder, no children | 8.2% | 5.8% | 10.8% |