| | Lake Forest, IL | Kenilworth, IL | United States |
| Population | 19,450 | 2,423 | 329,725,481 |
| Female Population | 51.5% | 51.0% | 50.5% |
| Male Population | 48.5% | 49.0% | 49.5% |
| Median Age | 46.4 | 40.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 19,392 | 2,506 | 309,327,143 |
| Population - 2000 | 20,059 | 2,494 | 285,036,114 |
| Population - 1990 | 17,836 | 2,402 | 251,960,433 |
| Pop. 2000 to Now | -3.4% | -2.1% | 15.6% |
| Pop. 1990 to Now | 8.7% | 1.7% | 30.8% |
| space4 | | | |
| Population Density | 1,130.8 | 3,985.2 | 93.4 |
| Land Area | 17.2 | 0.6 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lake Forest, IL | Kenilworth, IL | United States |
| Age 0 to 4 | 3.8% | 9.0% | 5.9% |
| Age 5 to 9 | 4.7% | 10.3% | 6.1% |
| Age 10 to 14 | 6.9% | 11.1% | 6.6% |
| Age 15 to 17 | 4.8% | 4.6% | 3.9% |
| Age 18 to 20 | 6.2% | 4.2% | 4.0% |
| Age 21 to 24 | 6.7% | 2.6% | 5.2% |
| Age 25 to 34 | 7.8% | 2.8% | 13.8% |
| Age 35 to 44 | 7.7% | 11.8% | 12.9% |
| Age 45 to 54 | 13.4% | 14.3% | 12.6% |
| Age 55 to 59 | 7.5% | 9.0% | 6.7% |
| Age 60 to 64 | 6.1% | 6.8% | 6.3% |
| Age 65 to 74 | 13.2% | 8.5% | 9.6% |
| Age 75 to 84 | 7.3% | 3.5% | 4.5% |
| Age 85 and over | 4.0% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lake Forest, IL | Kenilworth, IL | United States |
| White | 82.1% | 86.7% | 59.4% |
| Black | 1.0% | 0.0% | 12.2% |
| Asian | 7.2% | 2.4% | 5.6% |
| Native American | 0.2% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.8% | 0.7% | 0.4% |
| Two or More Races | 3.6% | 5.4% | 3.2% |
| Hispanic | 5.2% | 4.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lake Forest, IL | Kenilworth, IL | United States |
| Married Population | 57.1% | 70.4% | 49.8% |
| Currently Married | 56.6% | 70.1% | 48.0% |
| Married but Separated | 0.5% | 0.2% | 1.8% |
| Single Population | 42.9% | 29.6% | 50.2% |
| Never Married | 30.5% | 21.2% | 33.8% |
| Divorced | 6.3% | 5.7% | 10.8% |
| Widowed | 6.1% | 2.8% | 5.6% |
| space5 | | | |
| Household Size | 2.61 | 3.21 | 2.60 |
| Households | 7,014 | 755 | 124,010,992 |
| Family Households | 5,085 | 634 | 80,755,759 |
| Married couple, w/children | 34.9% | 49.2% | 30.5% |
| Married couple, no children | 54.1% | 41.5% | 42.9% |
| Non Family Households | 1,929 | 121 | 43,255,233 |
| Single householder, w/children | 4.8% | 2.8% | 15.8% |
| Single householder, no children | 6.2% | 6.5% | 10.8% |