Columbia County Flag

Columbia County

State:
Washington
County Seat:
Dayton

Columbia County's estimated 2026 population is 4,236 with a growth rate of 2.29% in the past year according to the most recent United States census data. Columbia County is the 38th largest county in Washington. The 2010 population was 4,094 and has seen a growth of 3.47% since that time.

4,236
Total Population
5
Population Density (mi²)
38
Population Rank (State)
95 2.29%
Annual Population Growth

Columbia County Population

Demographics

Economics and Income Statistics