This is Washington’s wealthiest county, study says. See how much residents make
When it comes to wealth, Western Washington has the market cornered.
All 10 of Washington’s richest counties can be found on the west side of the state, according to SmartAsset.
The financial advising website created an interactive map showing the wealthiest counties across the United States based on earnings, investment income and home value in 2025, the most recent data available.
Here’s which counties made the list:
What is the richest county in Washington State?
According to SmartAssest, the wealthiest county in Washington state in 2025 was King County, home to Seattle, Bellevue and Kirkland.
The county, which borders Puget Sound to the west and the Cascade mountains to the east, was the 25th richest county in the nation in terms of overall wealth.
An estimated 2.3 million called King County home as of July 2024, according to the latest data from U.S. Census.
How much income do King County residents earn?
King County residents make a median annual income of $122,148, earning $94,503 in median investment income, according to SmartAsset.
King County homes have a median value of $823,023, the personal finance website found.
In comparison, the average home in Washington state was valued at $585,669 as of Wednesday, Feb. 17, according to real estate website Zillow.
The average Seattle home value was $837,193 as of Wednesday, Zillow said.
How does Washington wealth compare to Oregon? Idaho?
King County compares favorably to other wealthy counties across the Pacific Northwest.
Residents in Idaho’s wealthiest county, Blaine County, boast a median annual income of $84,470 and median home value of $889,993, according to SmartAsset.
Folks living in Oregon’s richest county, Clackamas County, earned a median income of $100,360 per year, with a median home value of $595,099, SmartAsset found.
Where are the 10 richest counties in Washington state?
According to SmartAsset, these were the top 10 richest counties in Washington state based on overall wealth in 2025:
1. King County
- Median income: $122,148
- Median investment income: $94,503
- Median home value: $823,023
2. Snohomish County
- Median income: $107,982
- Median investment income: $34,319
- Median home value: $695,223
3. San Juan County
- Median income: $83,682
- Median investment income: $91,529
- Median home value: $903,287
4. Kitsap County
- Median income: $98,546
- Median investment income: $48,932
- Median home value: $548,181
5. Clark County
- Median income: $94,948
- Median home value: $519,950
- Investment income: $55,028
6. Pierce County
- Median income: $96,632
- Median investment income: $38,758
- Median home value: $526,387
7. Skamania County
- Median income: $90,085
- Median home value: $518,876
- Investment income: $73,694
8. Island County
- Median income: $88,358
- Median investment income: $47,774
- Median home value: $592,993
9. Thurston County
- Median income: $93,985
- Median investment income: $37,216
- Median home value: $492,899
10. Skagit County
- Median income: $85,474
- Median investment income: $53,118
- Median home value: $540,569
How did Smart Asset rank state’s wealthiest counties?
To rank Washington state’s wealthiest counties, Smart Asset compared each county’s investment income, property value and median income.
“We started the analysis by calculating the Investment Index for each county by evenly weighing the ordinary dividends, qualified dividends and net capital gains,” the website said. “From there we calculated the median home value and the median income for each county, and ranked them on all three metrics.”
This story was originally published February 19, 2026 at 5:00 AM with the headline "This is Washington’s wealthiest county, study says. See how much residents make."