The Seattle metropolitan area is located in the U.S. state of Washington and includes the three most populous counties—King, Snohomish, and Pierce—within the greater Puget Sound region. The United States Census Bureau officially defines the metropolitan area as the Seattle–Tacoma–Bellevue, WA Metropolitan Statistical Area, with an estimated population of 3,798,902, which is slightly more than half of Washington's population as of 2016, making it the 15th largest Metropolitan Statistical Area in the United States.
As defined by the United States Census Bureau, the Seattle metropolitan area is made up of the following (see Fig. STB):
Seattle–Bellevue–Everett metropolitan division
King County: Seattle and its immediate vicinity
Snohomish County: north of Seattle
Tacoma metropolitan division
Pierce County: south of Seattle
Based on commuting patterns, the adjacent metropolitan areas of Olympia, Bremerton, and Mount Vernon, along with a few smaller satellite urban areas, are grouped together in a wider labor market region known as the Seattle–Tacoma–Olympia Combined Statistical Area (CSA) (See Figure STO), commonly known as the Puget Sound region. The population of this wider region is 4,684,516—roughly two-thirds of Washington's population—as of 2016. The Seattle CSA is the 12th largest CSA, and the 13th largest primary census statistical area in the country. The additional metropolitan and micropolitan areas included are:
Bremerton–Silverdale metropolitan area
Kitsap County: west of Seattle, separated from the city by Puget Sound; connected to Seattle by ferry and to Tacoma by the Tacoma Narrows Bridge
Olympia metropolitan area
Thurston County: southwest of Seattle, at the south end of Puget Sound
Mount Vernon–Anacortes metropolitan area
Skagit County
Oak Harbor micropolitan area
Island County: northwest of Everett, encompassing Whidbey and Camano Islands in Puget Sound
Shelton micropolitan area
Mason County: west of Tacoma and northwest of Olympia
Census statistics
As of the 2010 census, there were 3,439,809 people, 1,357,475 households, and 845,966 families residing within the MSA. The racial makeup of the MSA were as followed: