| | Gainesville, MO | Shell Knob, MO | United States |
| Population | 660 | 1,579 | 329,725,481 |
| Female Population | 59.6% | 51.5% | 50.5% |
| Male Population | 40.5% | 48.5% | 49.5% |
| Median Age | 49.9 | 62.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 823 | 1,205 | 309,327,143 |
| Population - 2000 | 632 | 1,393 | 285,036,114 |
| Population - 1990 | 659 | 1,031 | 251,960,433 |
| Pop. 2000 to Now | 22.0% | -21.7% | 15.6% |
| Pop. 1990 to Now | 17.0% | 5.8% | 30.8% |
| space4 | | | |
| Population Density | 229.9 | 192.7 | 93.4 |
| Land Area | 2.9 | 8.2 | 3,531,905.4 |
| Water Area | 0.0 | 2.6 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Gainesville, MO | Shell Knob, MO | United States |
| Age 0 to 4 | 5.9% | 0.0% | 5.9% |
| Age 5 to 9 | 6.5% | 4.8% | 6.1% |
| Age 10 to 14 | 3.8% | 0.0% | 6.6% |
| Age 15 to 17 | 4.7% | 1.3% | 3.9% |
| Age 18 to 20 | 3.5% | 0.0% | 4.0% |
| Age 21 to 24 | 2.3% | 3.3% | 5.2% |
| Age 25 to 34 | 11.1% | 4.5% | 13.8% |
| Age 35 to 44 | 5.5% | 4.3% | 12.9% |
| Age 45 to 54 | 11.7% | 6.0% | 12.6% |
| Age 55 to 59 | 9.2% | 16.3% | 6.7% |
| Age 60 to 64 | 6.5% | 13.6% | 6.3% |
| Age 65 to 74 | 11.7% | 29.4% | 9.6% |
| Age 75 to 84 | 12.9% | 13.4% | 4.5% |
| Age 85 and over | 4.8% | 3.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Gainesville, MO | Shell Knob, MO | United States |
| White | 95.6% | 74.5% | 59.4% |
| Black | 1.2% | 0.0% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.6% | 15.1% | 3.2% |
| Hispanic | 2.6% | 10.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Gainesville, MO | Shell Knob, MO | United States |
| Married Population | 40.3% | 70.5% | 49.8% |
| Currently Married | 38.3% | 69.8% | 48.0% |
| Married but Separated | 2.0% | 0.7% | 1.8% |
| Single Population | 59.7% | 29.5% | 50.2% |
| Never Married | 23.9% | 5.1% | 33.8% |
| Divorced | 15.9% | 11.4% | 10.8% |
| Widowed | 19.9% | 12.9% | 5.6% |
| space5 | | | |
| Household Size | 2.03 | 2.01 | 2.60 |
| Households | 300 | 785 | 124,010,992 |
| Family Households | 157 | 560 | 80,755,759 |
| Married couple, w/children | 17.8% | 8.4% | 30.5% |
| Married couple, no children | 46.5% | 90.2% | 42.9% |
| Non Family Households | 143 | 225 | 43,255,233 |
| Single householder, w/children | 29.3% | 0.0% | 15.8% |
| Single householder, no children | 6.4% | 1.4% | 10.8% |