Jefferson County's 2026 population is estimated at 234,130, reflecting a 0.43% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Jefferson County is the 7th largest county in Missouri. The 2010 population was 219,130 and has grown 6.85% since 2010.
Overall: 40.3 years
Female: 41.1 years
Male: 39.7 years
There are 177,825 adults, (38,261 of whom are seniors) in Jefferson County.
Female: 114,708 (50%)
Male: 114,750 (50%)
The racial composition of Jefferson County includes 89.29% White, and smaller percentages for Asian, Black or African American, other race, Native American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 204,876 | 89.29% |
| Two or more races | 17,493 | 7.62% |
| Asian | 2,358 | 1.03% |
| Black or African American | 2,315 | 1.01% |
| Other race | 2,018 | 0.88% |
| Native American | 351 | 0.15% |
| Native Hawaiian or Pacific Islander | 47 | 0.02% |
Jefferson County 's average per capita income is $53,166. Household income levels show a median of $82,851. The poverty rate stands at 9.03%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $112,610 | $124,314 |
| Families | $98,453 | $112,063 |
| Households | $82,851 | $98,813 |
| Non Families | $44,776 | $60,053 |
Average Income
Median Household Income
Poverty Rate
