| | Yarmouth, ME | Westbrook, ME | United States |
| Population | 8,903 | 20,074 | 329,725,481 |
| Female Population | 54.4% | 53.4% | 50.5% |
| Male Population | 45.6% | 46.7% | 49.5% |
| Median Age | 44.8 | 37.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 8,344 | 17,521 | 309,327,143 |
| Population - 2000 | 8,360 | 16,142 | 285,036,114 |
| Population - 1990 | 7,862 | 16,121 | 251,960,433 |
| Pop. 2000 to Now | 2.9% | 19.4% | 15.6% |
| Pop. 1990 to Now | 9.4% | 19.5% | 30.8% |
| space4 | | | |
| Population Density | 666.8 | 1,167.9 | 93.4 |
| Land Area | 13.4 | 17.2 | 3,531,905.4 |
| Water Area | 9.6 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Yarmouth, ME | Westbrook, ME | United States |
| Age 0 to 4 | 3.2% | 4.9% | 5.9% |
| Age 5 to 9 | 5.8% | 3.5% | 6.1% |
| Age 10 to 14 | 7.1% | 5.3% | 6.6% |
| Age 15 to 17 | 8.3% | 3.2% | 3.9% |
| Age 18 to 20 | 2.7% | 2.8% | 4.0% |
| Age 21 to 24 | 3.2% | 4.3% | 5.2% |
| Age 25 to 34 | 10.1% | 21.3% | 13.8% |
| Age 35 to 44 | 9.7% | 11.5% | 12.9% |
| Age 45 to 54 | 15.7% | 11.8% | 12.6% |
| Age 55 to 59 | 9.1% | 8.1% | 6.7% |
| Age 60 to 64 | 6.5% | 5.0% | 6.3% |
| Age 65 to 74 | 9.6% | 9.9% | 9.6% |
| Age 75 to 84 | 6.1% | 5.4% | 4.5% |
| Age 85 and over | 2.8% | 2.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Yarmouth, ME | Westbrook, ME | United States |
| White | 92.9% | 87.1% | 59.4% |
| Black | 0.5% | 4.4% | 12.2% |
| Asian | 2.7% | 2.2% | 5.6% |
| Native American | 0.1% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 2.0% | 1.7% | 0.4% |
| Two or More Races | 0.3% | 3.2% | 3.2% |
| Hispanic | 1.5% | 1.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Yarmouth, ME | Westbrook, ME | United States |
| Married Population | 45.5% | 45.5% | 49.8% |
| Currently Married | 44.9% | 44.4% | 48.0% |
| Married but Separated | 0.6% | 1.0% | 1.8% |
| Single Population | 54.5% | 54.6% | 50.2% |
| Never Married | 30.2% | 36.5% | 33.8% |
| Divorced | 17.1% | 12.4% | 10.8% |
| Widowed | 7.2% | 5.7% | 5.6% |
| space5 | | | |
| Household Size | 2.53 | 2.26 | 2.60 |
| Households | 3,463 | 8,838 | 124,010,992 |
| Family Households | 2,353 | 4,691 | 80,755,759 |
| Married couple, w/children | 30.5% | 27.3% | 30.5% |
| Married couple, no children | 39.3% | 50.2% | 42.9% |
| Non Family Households | 1,110 | 4,147 | 43,255,233 |
| Single householder, w/children | 21.1% | 11.4% | 15.8% |
| Single householder, no children | 9.2% | 11.0% | 10.8% |