King County is a county located in the U.S. state of Washington. As of the 2010 census its population was 1,931,249. King is the most populous county in Washington, and the 14th most populous in the United States.
The county seat is Seattle, which is the state's largest city. About two-thirds of the county's population lives in the city's suburbs. King County ranks among the 100 highest-income counties in the United States.