| | Lansdowne, VA | Falls Church, VA | United States |
| Population | 13,029 | 14,494 | 329,725,481 |
| Female Population | 52.3% | 50.1% | 50.5% |
| Male Population | 47.7% | 49.9% | 49.5% |
| Median Age | 40.8 | 39.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 9,823 | 12,422 | 309,327,143 |
| Population - 2000 | 899 | 10,377 | 285,036,114 |
| Population - 1990 | 53 | 9,578 | 251,960,433 |
| Pop. 2000 to Now | 1,421.9% | 41.0% | 15.6% |
| Pop. 1990 to Now | 25,715.1% | 52.8% | 30.8% |
| space4 | | | |
| Population Density | 3,272.8 | 7,084.1 | 93.4 |
| Land Area | 4.0 | 2.0 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lansdowne, VA | Falls Church, VA | United States |
| Age 0 to 4 | 4.4% | 5.2% | 5.9% |
| Age 5 to 9 | 5.1% | 6.1% | 6.1% |
| Age 10 to 14 | 7.9% | 8.5% | 6.6% |
| Age 15 to 17 | 6.2% | 4.7% | 3.9% |
| Age 18 to 20 | 3.9% | 2.9% | 4.0% |
| Age 21 to 24 | 5.4% | 5.2% | 5.2% |
| Age 25 to 34 | 11.1% | 11.7% | 13.8% |
| Age 35 to 44 | 11.1% | 14.2% | 12.9% |
| Age 45 to 54 | 17.7% | 15.3% | 12.6% |
| Age 55 to 59 | 7.4% | 7.8% | 6.7% |
| Age 60 to 64 | 4.5% | 5.2% | 6.3% |
| Age 65 to 74 | 6.4% | 8.7% | 9.6% |
| Age 75 to 84 | 5.8% | 3.1% | 4.5% |
| Age 85 and over | 3.1% | 1.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lansdowne, VA | Falls Church, VA | United States |
| White | 63.3% | 70.7% | 59.4% |
| Black | 8.9% | 4.5% | 12.2% |
| Asian | 17.1% | 9.2% | 5.6% |
| Native American | 0.6% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.0% | 0.2% |
| Other | 0.4% | 0.3% | 0.4% |
| Two or More Races | 2.1% | 4.6% | 3.2% |
| Hispanic | 7.3% | 10.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lansdowne, VA | Falls Church, VA | United States |
| Married Population | 59.6% | 56.0% | 49.8% |
| Currently Married | 58.6% | 55.6% | 48.0% |
| Married but Separated | 1.0% | 0.4% | 1.8% |
| Single Population | 40.4% | 44.0% | 50.2% |
| Never Married | 26.6% | 32.6% | 33.8% |
| Divorced | 8.8% | 7.4% | 10.8% |
| Widowed | 5.1% | 4.0% | 5.6% |
| space5 | | | |
| Household Size | 2.72 | 2.57 | 2.60 |
| Households | 4,582 | 5,630 | 124,010,992 |
| Family Households | 3,483 | 3,643 | 80,755,759 |
| Married couple, w/children | 43.2% | 44.7% | 30.5% |
| Married couple, no children | 43.0% | 39.1% | 42.9% |
| Non Family Households | 1,099 | 1,987 | 43,255,233 |
| Single householder, w/children | 9.0% | 10.5% | 15.8% |
| Single householder, no children | 4.8% | 5.6% | 10.8% |