Seattle (pronounced /siːˈætəl/ ( listen) see-AT-əl) is the northernmost major city in the contiguous United States, and the largest city in the Pacific Northwest and in the state of Washington. A seaport situated on an isthmus between Puget Sound (an arm of the Pacific Ocean) and Lake Washington, about 100 miles (160 km) south of the Canada – United States border, it is named after Chief Sealth "Seattle", of the Duwamish and Suquamish native tribes. Seattle is the center of the Seattle–Tacoma–Bellevue metropolitan statistical area, the 15th largest in the United States, and the largest in the northwestern United States. Seattle is the county seat of King County and is the major economic, cultural and educational center in the region. As of April 2009, the city's population was approximately 617,000 within a metropolitan area of 4,158,000. The Port of Seattle and Seattle–Tacoma International Airport are major gateways to Asia, Alaska, and the rest of the world.

Seattle is the western terminus of I-90 and resides on the I-5 corridor, about 170 miles (270 km) north of Portland, Oregon/Vancouver, Washington and 140 miles (230 km) south of Vancouver in British Columbia, Canada. The city of Victoria, British Columbia's capital, is about 110 miles (180 km) to the northwest (about 90 miles (140 km) by passenger ferry) while the eastern Washington hub city of Spokane lies 280 miles (450 km) to the east.

The Seattle area has been inhabited for at least 4,000 years, but white settlement began only in the mid-19th century. The first permanent European-descended 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 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 1982, Seattle was known as the "Queen City". Seattle's current official nickname is the "Emerald City", the result of a contest held in 1981; 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 the rock music style known as "grunge," which was made famous by local groups Nirvana, Soundgarden, Alice in Chains, and Pearl Jam.

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 consistently rank Seattle and Minneapolis as the two most literate cities among America's largest cities Additionally, survey data from the United States Census Bureau indicate that Seattle has a higher percentage of college graduates than any other major American city, with approximately 53.8% of residents aged 25 and older holding a bachelor degree or higher.

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. Seattle has particularly strong information technology, aviation, architecture and recreational industries. It is particularly known as a hotbed of "green" technologies, stemming in part from the strong and relatively non-controversial stances its public leaders have taken on policies regarding urban design, building standards, clean energy and climate change (Seattle in February 2010 committed itself to becoming North America's first "climate neutral" city, with a goal of reaching zero net per capita greenhouse gas emissions by 2030).

Seattle is ranked as one of the most car-congested cities in the United States, and efforts to promote compact development and transportation choices are perennial policy issues. The railways and streetcars that once dominated its transportation system were largely replaced with an extensive network of bus routes 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. 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.