| | Lago Vista, TX | Willis, TX | United States |
| Population | 8,769 | 6,410 | 329,725,481 |
| Female Population | 47.7% | 42.8% | 50.5% |
| Male Population | 52.3% | 57.2% | 49.5% |
| Median Age | 53.4 | 37 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,093 | 5,908 | 309,327,143 |
| Population - 2000 | 4,507 | 3,985 | 285,036,114 |
| Population - 1990 | 2,199 | 2,764 | 251,960,433 |
| Pop. 2000 to Now | 76.2% | 78.7% | 15.6% |
| Pop. 1990 to Now | 261.2% | 157.7% | 30.8% |
| space4 | | | |
| Population Density | 625.1 | 1,354.3 | 93.4 |
| Land Area | 14.0 | 4.7 | 3,531,905.4 |
| Water Area | 1.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lago Vista, TX | Willis, TX | United States |
| Age 0 to 4 | 3.1% | 3.1% | 5.9% |
| Age 5 to 9 | 4.3% | 8.7% | 6.1% |
| Age 10 to 14 | 4.2% | 6.6% | 6.6% |
| Age 15 to 17 | 2.7% | 0.8% | 3.9% |
| Age 18 to 20 | 0.9% | 7.7% | 4.0% |
| Age 21 to 24 | 1.2% | 4.1% | 5.2% |
| Age 25 to 34 | 11.5% | 15.6% | 13.8% |
| Age 35 to 44 | 9.8% | 17.7% | 12.9% |
| Age 45 to 54 | 15.8% | 6.3% | 12.6% |
| Age 55 to 59 | 7.5% | 4.8% | 6.7% |
| Age 60 to 64 | 10.7% | 9.9% | 6.3% |
| Age 65 to 74 | 14.9% | 11.2% | 9.6% |
| Age 75 to 84 | 8.8% | 3.2% | 4.5% |
| Age 85 and over | 4.5% | 0.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lago Vista, TX | Willis, TX | United States |
| White | 77.7% | 39.2% | 59.4% |
| Black | 2.0% | 8.8% | 12.2% |
| Asian | 0.2% | 1.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.3% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.0% | 0.3% | 3.2% |
| Hispanic | 17.7% | 50.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lago Vista, TX | Willis, TX | United States |
| Married Population | 65.6% | 48.6% | 49.8% |
| Currently Married | 64.1% | 44.9% | 48.0% |
| Married but Separated | 1.5% | 3.7% | 1.8% |
| Single Population | 34.4% | 51.4% | 50.2% |
| Never Married | 17.0% | 37.0% | 33.8% |
| Divorced | 10.8% | 9.7% | 10.8% |
| Widowed | 6.6% | 4.7% | 5.6% |
| space5 | | | |
| Household Size | 2.32 | 3.06 | 2.60 |
| Households | 3,776 | 2,075 | 124,010,992 |
| Family Households | 2,588 | 1,582 | 80,755,759 |
| Married couple, w/children | 26.1% | 28.4% | 30.5% |
| Married couple, no children | 68.7% | 43.4% | 42.9% |
| Non Family Households | 1,188 | 493 | 43,255,233 |
| Single householder, w/children | 0.7% | 5.0% | 15.8% |
| Single householder, no children | 4.5% | 23.1% | 10.8% |