Johnson County's 2026 population is estimated at 163,836, reflecting a 1.16% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Johnson County is the 4th largest county in Iowa. The 2010 population was 131,344 and has grown 24.74% since 2010.
Data after 2023 is projected based on recent change
Overall: 31 years
Female: 31.5 years
Male: 30.6 years
There are 126,363 adults, (20,834 of whom are seniors) in Johnson County.
Female: 78,791 (50.3%)
Male: 77,848 (49.7%)
The racial composition of Johnson County includes 76.39% White, 7.7% Black or African American, 5.65% Asian, and smaller percentages for other race, Native American, Native Hawaiian or Pacific Islander and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 119,654 | 76.39% |
| Two or more races | 12,096 | 7.72% |
| Black or African American | 12,059 | 7.7% |
| Asian | 8,849 | 5.65% |
| Other race | 3,677 | 2.35% |
| Native American | 273 | 0.17% |
| Native Hawaiian or Pacific Islander | 31 | 0.02% |
Johnson County 's average per capita income is $54,856. Household income levels show a median of $74,935. The poverty rate stands at 17.07%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $133,357 | $171,866 |
| Families | $118,607 | $152,462 |
| Households | $74,935 | $108,874 |
| Non Families | $44,312 | $60,012 |
Average Income
Median Household Income
Poverty Rate
