How many people live in Allen County, KS?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 12,400 people living in Allen County, KS. That makes Allen County the 36th-most populous county in Kansas. It is home to 0.42% of people living in the state.
12.4K
population of Allen County, KS (2024)
0.42%
County share of the Kansas population (2024)
About 12,400 people lived in Allen County, KS in 2024.
Population estimates, 2000–2024
What are Allen County, KS’s age demographics?
About 2,700 Allen County, KS residents are aged 65 and older in 2024. That represents 21.6% of its population. For comparison, the age group represents 17.9% of Kansas’s population and 18% in the US overall.
Another 2,800 Allen County residents, or 22.2% of the population, were children under 18. For comparison, the age group represents 23.5% of Kansas’s population and 21.6% in the US overall.
A lower share of Allen County, KS's population is aged 25–44 than the US as a whole.
Population estimates by age group, (2024)
What are Allen County, KS’s racial and ethnic demographics?
Non-Hispanic white residents make up 88.4% of the Allen County, KS population, higher than the national share of 57.5%. Allen County, KS also has a larger share of people identifying as non-Hispanic two or more races (2.9%) than the US overall (2.5%).
In contrast, Allen County’s Hispanic population accounts for 4.6%, 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.
Allen County, KS has a higher share of a non-Hispanic white population than Kansas as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Allen County, KS is Iola with about 5,300 residents in 2024.
Cities and towns in Allen County, KS ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Iola | 5,309 |
| 2. | Humboldt | 1,817 |
| 3. | La Harpe | 488 |
| 4. | Gas | 466 |
| 5. | Moran | 463 |
| 6. | Carlyle | 289 |
| 7. | Humboldt | 270 |
| 8. | Osage | 263 |
| 9. | Salem | 247 |
| 10. | Cottage Grove | 224 |
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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.
