Seattle ( ) is a coastal port city and the largest city in the Pacific Northwest region of the United States. It is located in the state of Washington between an arm of the Pacific Ocean called Puget Sound and Lake Washington, about south of the Canada – United States border in King County, of which it is the county seat.

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 white 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 "bye and bye" 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. As of 2006, the city had an estimated population of 582,174 and an estimated metropolitan area population of approximately 3.2 million. Seattle is the hub and largest city of the Seattle metropolitan area, often called Puget Sound, which also includes Tacoma, Bellevue, and Everett. 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 the early 1980s; the reference is to the lush evergreen trees in the surrounding area. Seattle is also referred to informally as the "Gateway to Alaska," and "Jet City," the latter from the local influence of Boeing. Seattle residents are known as Seattleites.

Seattle is often regarded as the birthplace of grunge music, and 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 and second most literate in 2007. Moreover, analysis conducted in 2004 by the United States Census Bureau of 2002 survey data indicated that Seattle was the most educated large city in the U.S. with 48.8 percent of residents 25 and older having at least bachelor degrees. Based on per capita income, in 2006 the Seattle metropolitan area ranked 17th out of 363 metropolitan areas in a study by the Census Bureau.

Seattle was the site of the 1999 meeting of the World Trade Organization, and the attendant demonstrations by anti-globalization activists. The city is also home to the Pride Foundation, which became the most-funded gay rights organisation in the US when former Microsoft co-founder Ric Weiland bequeathed $65 million to the foundation as well as ten other organisations.