How many people live in Cass County, IA?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 13,000 people living in Cass County, IA. That makes Cass County the 58th-most populous county in Iowa. It is home to 0.4% of people living in the state.
13K
population of Cass County, IA (2024)
0.4%
County share of the Iowa population (2024)
About 13,000 people lived in Cass County, IA in 2024.
Population estimates, 2000–2024
What are Cass County, IA’s age demographics?
About 3,200 Cass County residents are aged 65 and older in 2024. That represents 24.2% of its population. For comparison, the age group represents 18.9% of Iowa’s population and 18% in the US overall.
Another 2,900 Cass County residents, or 22.6% 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 Cass County, IA's population is aged 65 or older than the US as a whole.
Population estimates by age group, (2024)
What are Cass County, IA’s racial and ethnic demographics?
Non-Hispanic white residents make up 92.7% of the Cass County, IA population, higher than the national share of 57.5%. Cass County, IA also has a larger share of people identifying as non-Hispanic Native Hawaiian and other Pacific Islander (1.9%) than the US overall (0.2%).
In contrast, Cass County’s Hispanic population accounts for 3%, below the 20% nationwide, and the non-Hispanic Black or African American population makes up 0.59% 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.
Cass 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 Cass County, IA is Atlantic with about 6,700 residents in 2024.
Cities and towns in Cass County, IA ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Atlantic | 6,717 |
| 2. | Griswold | 975 |
| 3. | Anita | 953 |
| 4. | Lewis | 358 |
| 5. | Massena | 352 |
| 6. | Cumberland | 248 |
| 7. | Marne | 109 |
| 8. | Wiota | 91 |
| 9. | Balance of Cass County | 3,221 |
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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.
