Sioux County's 2026 population is estimated at 36,864, reflecting a 0.42% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Sioux County is the 19th largest county in Iowa. The 2010 population was 33,755 and has grown 9.21% since 2010.
Data after 2023 is projected based on recent change
Overall: 33.8 years
Female: 34.5 years
Male: 33.5 years
There are 26,375 adults, (5,866 of whom are seniors) in Sioux County.
Female: 17,892 (49.4%)
Male: 18,320 (50.6%)
The racial composition of Sioux County includes 85.03% White, 6.86% other race, and smaller percentages for Black or African American, Asian, Native American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 30,791 | 85.03% |
| Other race | 2,483 | 6.86% |
| Two or more races | 2,391 | 6.6% |
| Black or African American | 214 | 0.59% |
| Asian | 197 | 0.54% |
| Native American | 130 | 0.36% |
| Native Hawaiian or Pacific Islander | 6 | 0.02% |
Sioux County 's average per capita income is $50,919. Household income levels show a median of $86,098. The poverty rate stands at 6.67%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $110,255 | - |
| Families | $104,096 | $122,801 |
| Households | $86,098 | $104,988 |
| Non Families | $39,127 | $48,312 |
Average Income
Median Household Income
Poverty Rate