| | Marysville, WA | Kennewick, WA | United States |
| Population | 69,957 | 83,082 | 329,725,481 |
| Female Population | 50.2% | 50.5% | 50.5% |
| Male Population | 49.9% | 49.5% | 49.5% |
| Median Age | 37.4 | 35.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 60,206 | 74,448 | 309,327,143 |
| Population - 2000 | 25,315 | 54,693 | 285,036,114 |
| Population - 1990 | 10,328 | 42,155 | 251,960,433 |
| Pop. 2000 to Now | 182.0% | 54.5% | 15.6% |
| Pop. 1990 to Now | 591.3% | 100.5% | 30.8% |
| space4 | | | |
| Population Density | 3,394.0 | 3,026.8 | 93.4 |
| Land Area | 20.6 | 27.4 | 3,531,905.4 |
| Water Area | 0.3 | 1.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Marysville, WA | Kennewick, WA | United States |
| Age 0 to 4 | 7.0% | 7.4% | 5.9% |
| Age 5 to 9 | 6.2% | 8.1% | 6.1% |
| Age 10 to 14 | 6.0% | 6.4% | 6.6% |
| Age 15 to 17 | 3.6% | 4.2% | 3.9% |
| Age 18 to 20 | 4.0% | 3.8% | 4.0% |
| Age 21 to 24 | 4.6% | 5.0% | 5.2% |
| Age 25 to 34 | 14.8% | 14.7% | 13.8% |
| Age 35 to 44 | 14.8% | 12.9% | 12.9% |
| Age 45 to 54 | 12.7% | 10.4% | 12.6% |
| Age 55 to 59 | 6.9% | 5.8% | 6.7% |
| Age 60 to 64 | 6.3% | 6.2% | 6.3% |
| Age 65 to 74 | 8.4% | 9.4% | 9.6% |
| Age 75 to 84 | 3.2% | 3.8% | 4.5% |
| Age 85 and over | 1.6% | 2.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Marysville, WA | Kennewick, WA | United States |
| White | 69.8% | 62.7% | 59.4% |
| Black | 2.0% | 1.9% | 12.2% |
| Asian | 7.0% | 2.3% | 5.6% |
| Native American | 1.1% | 0.5% | 0.6% |
| Hawaiian, Pacific Islander | 0.5% | 0.0% | 0.2% |
| Other | 0.4% | 0.2% | 0.4% |
| Two or More Races | 6.1% | 3.0% | 3.2% |
| Hispanic | 13.1% | 29.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Marysville, WA | Kennewick, WA | United States |
| Married Population | 53.8% | 51.2% | 49.8% |
| Currently Married | 52.5% | 49.7% | 48.0% |
| Married but Separated | 1.3% | 1.5% | 1.8% |
| Single Population | 46.2% | 48.8% | 50.2% |
| Never Married | 28.1% | 31.2% | 33.8% |
| Divorced | 12.8% | 13.2% | 10.8% |
| Widowed | 5.3% | 4.3% | 5.6% |
| space5 | | | |
| Household Size | 2.74 | 2.69 | 2.60 |
| Households | 25,396 | 30,382 | 124,010,992 |
| Family Households | 18,218 | 20,794 | 80,755,759 |
| Married couple, w/children | 31.8% | 29.1% | 30.5% |
| Married couple, no children | 44.4% | 41.8% | 42.9% |
| Non Family Households | 7,178 | 9,588 | 43,255,233 |
| Single householder, w/children | 12.3% | 19.3% | 15.8% |
| Single householder, no children | 11.6% | 9.8% | 10.8% |