The Seattle metropolitan area is an urban conglomeration in the U.S. state of Washington that comprises Seattle, its surrounding satellites and suburbs. The United States Census Bureau defines the Seattle–Tacoma–Bellevue, WA metropolitan statistical area as the three most populous counties in the state: King, Pierce, and Snohomish. Seattle has the 15th largest metropolitan statistical area (MSA) in the United States with a population of 4,018,762 as of the 2020 census, over half of Washington's total population.

Washington, officially the State of Washington, is a state in the Pacific Northwest region of the United States. It is often referred to as Washington state or Washington State to distinguish it from the national capital, both named for George Washington. Washington borders the Pacific Ocean to the west, Oregon to the south, Idaho to the east, and the Canadian province of British Columbia to the north. The state was formed from the western part of the Washington Territory, which was ceded by the British Empire in the Oregon Treaty of 1846. It was admitted to the Union as the 42nd state in 1889. Olympia is the state capital, and the most populous city is Seattle.