King County is located in the U.S. state of Washington. The population in the 2000 census was 1,737,034 and in 2006 was an estimated 1,835,300. By population, King is the largest county in Washington, and the 12th largest in the United States. As of 2006, the county had a population comparable to that of the state of Nebraska. King County apartments for rent comparison page shows most up to date rent information on King County apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.