How many people live in Columbia County, WA?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 4,000 people living in Columbia County, WA. That makes Columbia County the 38th-most populous county in Washington state. It is home to 0.05% of people living in the state.
4.03K
population of Columbia County, WA (2024)
0.05%
County share of the Washington population (2024)
About 4,000 people lived in Columbia County, WA in 2024.
Population estimates, 2000–2024
What are Columbia County, WA’s age demographics?
About 1,200 Columbia County residents are aged 65 and older in 2024. That represents 30% of its population. For comparison, the age group represents 17.4% of Washington’s population and 18% in the US overall.
Another 725 Columbia County residents, or 18% of the population, were children under 18. For comparison, the age group represents 20.9% of Washington’s population and 21.6% in the US overall.
A higher share of Columbia County, WA's population is aged 65 or older than the US as a whole.
Population estimates by age group, (2024)
What are Columbia County, WA’s racial and ethnic demographics?
Non-Hispanic white residents make up 82.7% of the Columbia County, WA population, higher than the national share of 57.5%. Columbia County, WA 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, Columbia County’s non-Hispanic Black or African American population accounts for 0.94%, below the 12.6% nationwide, and the Hispanic population makes up 8.4% of the county, compared with 20% 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.
Columbia County, WA has a higher share of a non-Hispanic white population than Washington as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Columbia County, WA is Dayton with about 2,500 residents in 2024.
Cities and towns in Columbia County, WA ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Dayton | 2,471 |
| 2. | Starbuck | 138 |
| 3. | Balance of Columbia County | 1,416 |
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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.
