County facts · Population · October 25, 2026
Washington Population by County, 2025 Census Estimates
Washington population by county: July 2025 Census estimates for all 39 counties, change since 2020, density, and a link to each official parcel map.
Looking for Washington population by county? The Census Bureau estimates that Washington had 8,001,020 residents on July 1, 2025, spread across 39 counties. King County is the most populous, with 2,344,939 people (29% of the state), and Garfield County is the least populous, with 2,416.
The table below lists every county with its 2025 estimate, its April 2020 starting point, the change, people per square mile, and a link to its official parcel viewer.
Washington population at a glance
- Counties: 39
- Statewide, July 1, 2025: 8,001,020 (April 1, 2020 estimates base: 7,707,519; change +293,501, +3.8%)
- Most populous: King County (2,344,939); least populous: Garfield County (2,416)
- Median county: about 71,165 residents (half of the counties are smaller)
- The 5 largest counties hold 66% of all Washington residents
- Counties with 1,000,000+ residents: 1 · 100,000+: 14 · under 10,000: 4
- Statewide density: about 120 people per square mile of land
Washington population by county, July 2025 (all 39)
Percent change runs from the April 1, 2020 estimates base to July 1, 2025. People per square mile is the July 2025 estimate divided by the county's land area in the Census Bureau's 2020 Gazetteer file, so lakes and bays are left out.
How Washington's population is spread out
Grouping the counties by size shows how concentrated the state is:
| Residents (July 2025) | Counties | Total residents | Share of state |
|---|---|---|---|
| 1,000,000 or more | 1 | 2,344,939 | 29% |
| 250,000 to 999,999 | 7 | 3,754,227 | 47% |
| 100,000 to 249,999 | 6 | 914,313 | 11% |
| 25,000 to 99,999 | 13 | 818,188 | 10% |
| 10,000 to 24,999 | 8 | 150,406 | 2% |
| Under 10,000 | 4 | 18,947 | 0% |
8 counties with at least 250,000 residents hold 76% of the state's population.
Most and least densely populated
The most crowded counties by people per square mile of land:
- King County: 1,109 per sq mi (2,344,939 people on 2,115 sq mi)
- Clark County: 847 per sq mi (532,119 people on 628 sq mi)
- Kitsap County: 717 per sq mi (283,374 people on 395 sq mi)
- Pierce County: 567 per sq mi (946,288 people on 1,668 sq mi)
- Thurston County: 421 per sq mi (304,261 people on 722 sq mi)
The most thinly settled:
- Garfield County: 3.4 per sq mi (2,416 people on 711 sq mi)
- Ferry County: 3.4 per sq mi (7,517 people on 2,203 sq mi)
- Columbia County: 4.8 per sq mi (4,141 people on 869 sq mi)
- Lincoln County: 5.2 per sq mi (11,982 people on 2,311 sq mi)
- Skamania County: 7.6 per sq mi (12,669 people on 1,658 sq mi)
About these numbers
- They are estimates. Between censuses the Census Bureau's Population Estimates Program updates county totals each year from births, deaths and migration records. The next full count is the 2030 census.
- The base is April 1, 2020. The estimates start from an April 1, 2020 "estimates base" built from the 2020 census, which is why it is slightly different from the published census count.
- Each new release revises the past. A newer vintage can change earlier years as well, so compare numbers from the same release, as this page does.
- Statewide total. The counties add up exactly to the statewide figure of 8,001,020 in the same file.
Using population numbers in a land search
- Big counties, busy offices. In the most populous counties, parcel maps and deed records are usually online and searchable, but recording and permit offices are busier. Allow for that if you are on a deadline.
- Small counties, fewer sales. In counties with only a few thousand people, land changes hands less often, so there are fewer recent sales to compare a price with. Recorded deeds and the local assessor's sales records are the best source.
- Density hints at lot size. A low people-per-square-mile figure usually means farms, ranches and timber tracts; a high one means subdivided lots. The parcel viewer shows the actual parcel lines.
- Check the official map. Use the parcel viewer link in the table for boundaries, parcel numbers and owner names, then confirm anything important with the local assessor and the office that records deeds.
Related guides
- Fastest growing counties in Washington
- Largest counties in Washington
- Washington county GIS websites by viewer
- Washington plat maps
- Washington statewide parcel map
- Washington landowner maps for hunting
- Most populous counties in the US
- Where people are moving in the US
More: All Washington counties on Platbookmapper
Sources
- U.S. Census Bureau, Population Estimates Program, county totals, Vintage 2025 (April 1, 2020 estimates base and July 1, 2020–2025 estimates, with components of change). Statewide totals are the sum of the counties and match the file's state row.
- U.S. Census Bureau Gazetteer files, 2020 county land and water area (for people per square mile).
- Platbookmapper county GIS directory (live data file behind our county pages, pulled October 25, 2026) for each official parcel viewer.