The Seattle SuperSonics (or simply, Sonics) are an American professional basketball team based in Seattle, Washington. Currently playing in the Northwest Division of the National Basketball Association (NBA), they won the NBA Championship in 1979. Of the three current major professional sports teams in Seattle—the Seattle Mariners, the Seattle Seahawks, and the Sonics—the Sonics are the only one to have won a championship. (It should be noted, however, that the Seattle Metropolitans won the 1917 Stanley Cup, and the Seattle Storm won the WNBA Championship in 2004.) From the late 1970s through 1985, the Sonics' mascot was The Wheedle; since 1993, their mascot has been Squatch.

The team was owned by Sam Schulman from its 1967 inception until 1983; it has since been owned by Barry Ackerley, from 1983–2001, the Basketball Club of Seattle (headed by Starbucks chairman Howard Schultz), from 2001–2006, and currently, by Oklahoma City businessman Clay Bennett. The team's current ownership group is seeking to relocate the team to Oklahoma City , either before the 2008-2009 season or at the end of the team's lease in Seattle's Key Arena in 2010, after support never materialized for a proposed new $500-million arena.