The U.S. state of Washington has 29 statistical areas that have been delineated by the Office of Management and Budget (OMB). On July 21, 2023, the OMB delineated six combined statistical areas, 13 metropolitan statistical areas, and ten micropolitan statistical areas in Washington. As of 2023, the largest of these is the Seattle-Tacoma, WA CSA, anchored by Washington's largest city, Seattle and including its capital, Olympia.
The state historically had three metropolitan areas: Seattle, Spokane, and Tacoma. Seattle and Tacoma were eventually merged, while other metropolitan areas were added in the 1970s and 1980s. There are 13 metropolitan areas that include areas in Washington; the largest is SeattleâÂÂTacomaâÂÂBellevue, which includes half of the state's population.