RANKING · 2020 CENSUS · 39 SHOWN OF 39

Largest by population, Washington counties · 2020

The most populous Washington counties as of the 2020 population estimates. This list covers the 39 counties in Washington that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros ZIP codes

RELATEDFastest growing Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR1990 2000 2010 2020 2025

RANKPLACESTATETOTAL POPULATIONVS 2000

01King County, WAWA2,269,675+31%

02Pierce County, WAWA921,130+31%

03Snohomish County, WAWA827,957+37%

04Spokane County, WAWA539,339+29%

05Clark County, WAWA503,311+46%

06Thurston County, WAWA294,793+42%

07Kitsap County, WAWA275,611+19%

08Yakima County, WAWA256,728+15%

09Whatcom County, WAWA226,847+36%

10Benton County, WAWA206,873+45%

11Skagit County, WAWA129,523+26%

12Cowlitz County, WAWA110,730+19%

13Grant County, WAWA99,123+33%

14Franklin County, WAWA96,749+96%

15Island County, WAWA86,857+21%

16Lewis County, WAWA82,149+20%

17Chelan County, WAWA79,074+19%

18Clallam County, WAWA77,155+20%

19Grays Harbor County, WAWA75,636+13%

20Mason County, WAWA65,726+33%

21Walla Walla County, WAWA62,584+13%

22Whitman County, WAWA47,973+18%

23Stevens County, WAWA46,445+16%

24Kittitas County, WAWA44,337+33%

25Douglas County, WAWA42,938+32%

26Okanogan County, WAWA42,104+6%

27Jefferson County, WAWA32,977+27%

28Pacific County, WAWA23,365+11%

29Klickitat County, WAWA22,735+19%

30Asotin County, WAWA22,285+8%

31Adams County, WAWA20,613+25%

32San Juan County, WAWA17,788+26%

33Pend Oreille County, WAWA13,401+14%

34Skamania County, WAWA12,036+22%

35Lincoln County, WAWA10,876+7%

36Ferry County, WAWA7,178−1%

37Wahkiakum County, WAWA4,422+16%

38Columbia County, WAWA3,952−3%

39Garfield County, WAWA2,286−5%

SHOWING 1–39 OF 39

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU DECENNIAL CENSUS