Washington Population By County in 2021 (ACS-5Yrs)

Updated on February 28, 2025.

Based on the US Census ACS-5Yrs estimates, in 2021, the total population of Washington was 7.62M. Among all Washington counties, King was the most populated county (2.24M), followed by Pierce (910.23K), and then Snohomish (820.02K).

On the other hand, the least populated counties were: Garfield (2.28K), Columbia (3.97K), and Wahkiakum (4.37K).

The chart and table below shows the population of each county and the percentage of Washington population in each county.

You can see similar information for other states and by state for the United States.

Washington Population By County in 2021
County
Population
% of State Population
King 2,240,876 29.42
Pierce 910,225 11.95
Snohomish 820,024 10.77
Spokane 531,477 6.98
Clark 496,494 6.52
Thurston 290,642 3.82
Kitsap 273,072 3.59
Yakima 255,151 3.35
Whatcom 224,533 2.95
Benton 204,551 2.69
Skagit 128,228 1.68
Cowlitz 109,457 1.44
Grant 97,874 1.29
Franklin 95,313 1.25
Island 85,938 1.13
Lewis 81,214 1.07
Chelan 78,508 1.03
Clallam 76,727 1.01
Grays Harbor 74,737 0.98
Mason 64,964 0.85
Walla Walla 62,168 0.82
Whitman 48,197 0.63
Stevens 46,057 0.61
Kittitas 44,147 0.58
Douglas 42,622 0.56
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