How many people live in Decatur County, IA?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 7,700 people living in Decatur County, IA. That makes Decatur County the 86th-most populous county in Iowa. It is home to 0.24% of people living in the state.
7.66K
population of Decatur County, IA (2024)
0.24%
County share of the Iowa population (2024)
About 7,700 people lived in Decatur County, IA in 2024.
Population estimates, 2000–2024
What are Decatur County, IA’s age demographics?
About 1,700 Decatur County, IA residents are aged 65 and older in 2024. That represents 21.7% of its population. For comparison, the age group represents 18.9% of Iowa’s population and 18% in the US overall.
Another 1,700 Decatur County residents, or 22% of the population, were children under 18. For comparison, the age group represents 22.5% of Iowa’s population and 21.6% in the US overall.
A higher share of Decatur County, IA's population is aged 18–24 than the US as a whole.
Population estimates by age group, (2024)
What are Decatur County, IA’s racial and ethnic demographics?
Non-Hispanic white residents make up 90.6% of the Decatur County, IA population, higher than the national share of 57.5%.
In contrast, Decatur County’s Hispanic population accounts for 4.2%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 2.1% of the county, compared with 12.6% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Decatur County, IA has a higher share of a non-Hispanic white population than Iowa as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Decatur County, IA is Lamoni with about 2,100 residents in 2024.
Cities and towns in Decatur County, IA ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Lamoni | 2,072 |
| 2. | Leon | 1,779 |
| 3. | Grand River | 192 |
| 4. | Davis City | 178 |
| 5. | Van Wert | 175 |
| 6. | Decatur | 174 |
| 7. | Garden Grove | 173 |
| 8. | Weldon | 134 |
| 9. | Pleasanton | 32 |
| 10. | Le Roy | 10 |
Keep exploring
Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
