| | West Linn, OR | Seaside, OR | United States |
| Population | 27,173 | 7,058 | 329,725,481 |
| Female Population | 50.9% | 55.4% | 50.5% |
| Male Population | 49.1% | 44.6% | 49.5% |
| Median Age | 44.2 | 51.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 25,194 | 6,497 | 309,327,143 |
| Population - 2000 | 22,261 | 5,900 | 285,036,114 |
| Population - 1990 | 16,367 | 5,359 | 251,960,433 |
| Pop. 2000 to Now | 20.2% | 17.4% | 15.6% |
| Pop. 1990 to Now | 63.4% | 29.2% | 30.8% |
| space4 | | | |
| Population Density | 3,668.1 | 1,810.7 | 93.4 |
| Land Area | 7.4 | 3.9 | 3,531,905.4 |
| Water Area | 0.7 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | West Linn, OR | Seaside, OR | United States |
| Age 0 to 4 | 5.1% | 1.8% | 5.9% |
| Age 5 to 9 | 7.4% | 4.5% | 6.1% |
| Age 10 to 14 | 7.6% | 6.8% | 6.6% |
| Age 15 to 17 | 4.7% | 1.5% | 3.9% |
| Age 18 to 20 | 4.1% | 3.8% | 4.0% |
| Age 21 to 24 | 2.4% | 4.0% | 5.2% |
| Age 25 to 34 | 7.2% | 10.0% | 13.8% |
| Age 35 to 44 | 12.5% | 10.6% | 12.9% |
| Age 45 to 54 | 15.3% | 13.8% | 12.6% |
| Age 55 to 59 | 8.9% | 7.1% | 6.7% |
| Age 60 to 64 | 7.2% | 7.3% | 6.3% |
| Age 65 to 74 | 11.5% | 17.5% | 9.6% |
| Age 75 to 84 | 4.4% | 7.6% | 4.5% |
| Age 85 and over | 1.7% | 3.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | West Linn, OR | Seaside, OR | United States |
| White | 82.3% | 89.3% | 59.4% |
| Black | 1.3% | 2.6% | 12.2% |
| Asian | 5.2% | 1.2% | 5.6% |
| Native American | 0.1% | 0.9% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.0% | 0.2% |
| Other | 0.2% | 0.0% | 0.4% |
| Two or More Races | 3.9% | 0.1% | 3.2% |
| Hispanic | 6.8% | 5.9% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | West Linn, OR | Seaside, OR | United States |
| Married Population | 63.0% | 42.2% | 49.8% |
| Currently Married | 62.0% | 41.1% | 48.0% |
| Married but Separated | 1.0% | 1.1% | 1.8% |
| Single Population | 37.0% | 57.8% | 50.2% |
| Never Married | 22.5% | 25.8% | 33.8% |
| Divorced | 10.8% | 24.1% | 10.8% |
| Widowed | 3.8% | 7.9% | 5.6% |
| space5 | | | |
| Household Size | 2.70 | 2.03 | 2.60 |
| Households | 9,998 | 3,441 | 124,010,992 |
| Family Households | 7,536 | 1,496 | 80,755,759 |
| Married couple, w/children | 41.4% | 24.7% | 30.5% |
| Married couple, no children | 45.3% | 51.1% | 42.9% |
| Non Family Households | 2,462 | 1,945 | 43,255,233 |
| Single householder, w/children | 7.8% | 9.2% | 15.8% |
| Single householder, no children | 5.5% | 15.0% | 10.8% |