| | Fairfield, ME | Lewiston, ME | United States |
| Population | 6,490 | 36,615 | 329,725,481 |
| Female Population | 51.4% | 50.8% | 50.5% |
| Male Population | 48.6% | 49.2% | 49.5% |
| Median Age | 48.7 | 40.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,740 | 36,583 | 309,327,143 |
| Population - 2000 | 6,573 | 35,690 | 285,036,114 |
| Population - 1990 | 6,718 | 39,757 | 251,960,433 |
| Pop. 2000 to Now | -0.3% | 1.5% | 15.6% |
| Pop. 1990 to Now | -2.5% | -8.9% | 30.8% |
| space4 | | | |
| Population Density | 120.7 | 1,072.3 | 93.4 |
| Land Area | 53.8 | 34.1 | 3,531,905.4 |
| Water Area | 0.8 | 1.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Fairfield, ME | Lewiston, ME | United States |
| Age 0 to 4 | 2.3% | 5.7% | 5.9% |
| Age 5 to 9 | 4.8% | 5.7% | 6.1% |
| Age 10 to 14 | 4.1% | 4.6% | 6.6% |
| Age 15 to 17 | 5.8% | 4.2% | 3.9% |
| Age 18 to 20 | 3.3% | 5.3% | 4.0% |
| Age 21 to 24 | 4.1% | 5.9% | 5.2% |
| Age 25 to 34 | 6.8% | 13.0% | 13.8% |
| Age 35 to 44 | 12.3% | 10.6% | 12.9% |
| Age 45 to 54 | 20.8% | 12.2% | 12.6% |
| Age 55 to 59 | 6.3% | 8.8% | 6.7% |
| Age 60 to 64 | 12.7% | 6.2% | 6.3% |
| Age 65 to 74 | 11.2% | 9.1% | 9.6% |
| Age 75 to 84 | 3.8% | 6.2% | 4.5% |
| Age 85 and over | 1.8% | 2.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Fairfield, ME | Lewiston, ME | United States |
| White | 94.2% | 82.7% | 59.4% |
| Black | 0.6% | 7.0% | 12.2% |
| Asian | 0.0% | 2.0% | 5.6% |
| Native American | 0.2% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 3.6% | 5.9% | 3.2% |
| Hispanic | 1.4% | 2.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Fairfield, ME | Lewiston, ME | United States |
| Married Population | 43.0% | 43.0% | 49.8% |
| Currently Married | 43.0% | 41.3% | 48.0% |
| Married but Separated | 0.0% | 1.7% | 1.8% |
| Single Population | 57.0% | 57.0% | 50.2% |
| Never Married | 30.0% | 34.3% | 33.8% |
| Divorced | 19.3% | 15.5% | 10.8% |
| Widowed | 7.7% | 7.3% | 5.6% |
| space5 | | | |
| Household Size | 2.18 | 2.20 | 2.60 |
| Households | 2,956 | 15,588 | 124,010,992 |
| Family Households | 1,490 | 8,254 | 80,755,759 |
| Married couple, w/children | 31.5% | 25.8% | 30.5% |
| Married couple, no children | 47.7% | 46.0% | 42.9% |
| Non Family Households | 1,466 | 7,334 | 43,255,233 |
| Single householder, w/children | 12.1% | 17.9% | 15.8% |
| Single householder, no children | 8.7% | 10.3% | 10.8% |