COUNTY · WA
King County, Washington
King County is a county in Washington with FIPS code 53033 and an estimated population of 2,271,380 (Census 2023), 1st largest of 39 in the state.
County facts
- Name
- King County
- State
- Washington
- Type
- county
- FIPS code
- 53033
- State FIPS
- 53
- Population (2023)
- 2,271,380
- Change since 2020
- -0.1%
- State rank
- 1 of 39
Population is the Census Bureau’s Vintage 2023 estimate.
Major cities in King County
Other counties in Washington
Questions
What is the FIPS code for King County?
King County, Washington has the five-digit FIPS code 53033: 53 for the state and 033 for the county.
What state is King County in?
King County is in Washington.
How do I know if an address is in this county?
Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.
Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.