Seattle (pronounced /siːˈæɾəl/ ( listen), us dict: sē·ăt′·əl) is a coastal city and major seaport located in the Pacific Northwest region of the United States. Situated in the western part of Washington State on an isthmus between Puget Sound (an arm of the Pacific Ocean) and Lake Washington, about 96 miles (154 km) south of the Canada – United States border, it is named after Chief Sealth, of the Duwamish and Suquamish tribes. The encompassing Seattle-Tacoma-Bellevue metropolitan statistical area is the 15th largest in the United States, and the largest in the U.S. Pacific Northwest. The major economic, cultural and educational center in the region, Seattle is the county seat of King County. As of April 1, 2009, the city had an estimated municipal population of 602,000, making it the twenty-fifth most populous city in the U.S. and a metropolitan area population of 3,344,813.

The Seattle area has been inhabited for at least 4,000 years, but European settlement began only in the mid-19th century. The first permanent European settlers—Arthur A. Denny and those subsequently known as the Denny Party—arrived November 13, 1851. Early settlements in the area were called "New York-Alki" ("Alki" meaning "by and by" in the local Chinook Jargon) and "Duwamps". In 1853, Doc Maynard suggested that the main settlement be renamed "Seattle", an anglicized rendition of the name of Sealth, the chief of the two local tribes. From 1869 until 1882, Seattle was known as the "Queen City". Seattle's current official nickname is the "Emerald City", the result of a contest held in the early 1980s; the reference is to the lush evergreen forests of the area. Seattle is also referred to informally as the "Gateway to Alaska", "Rain City", and "Jet City", the last from the local influence of Boeing. Seattle residents are known as Seattleites.

Seattle is the birthplace of rock legend Jimi Hendrix and grunge, including Nirvana, Alice in Chains, Pearl Jam, and Soundgarden. Bruce Lee and Brandon Lee are also buried at Lakeview cemetery. Seattle has a reputation for heavy coffee consumption; coffee companies founded or based in Seattle include Starbucks, Seattle's Best Coffee, and Tully's. There are also many successful independent artisanal espresso roasters and cafes. Researchers at Central Connecticut State University ranked Seattle the most literate city of America's sixty-nine largest cities in 2005 and 2006, second most literate in 2007 (after Minneapolis), and tied with Minneapolis in 2008. Additionally, survey data by the United States Census Bureau indicated that Seattle was the most educated city in the U.S., with 52.5% of residents aged 25 and older having a bachelor's degree. In terms of per capita income, a study by the U.S. Bureau of Economic Analysis ranked the Seattle metropolitan area 17th out of 363 metropolitan areas in 2006.

The railways and streetcars that once dominated its transportation system have largely been replaced with an extensive bus route for those living near the city center, and the city's outward growth caused automobiles to become the main mode of transportation for much of the population in the middle to late twentieth century. As a result, Seattle is ranked as one of the most congested cities in the United States. However, efforts to reverse this trend at the municipal and state levels have resulted in new commuter rail service that connects Seattle to Everett and Tacoma, a regional Link Light Rail system that extends south from the city core, and an inner-city South Lake Union Streetcar network in the South Lake Union area. Extension of the light rail to the Seattle-Tacoma International Airport is expected by the end of 2009, and to surrounding areas such as the University of Washington, Bellevue and Redmond in the years to come.