Seattle Sounders FC is a professional soccer club based in Seattle, competing in Major League Soccer (MLS) as a member of the Western Conference. Established on November 13, 2007, and debuting in 2009, the club is a "phoenix" franchise that carries on the name of earlier Seattle teams, playing its home matches at Lumen Field. The Sounders have been among the league's most successful teams, winning the MLS Cup in 2016 and 2019, the Supporters' Shield in 2014, and four U.S. Open Cups, while making history in 2022 as the first MLS team to win the modern CONCACAF Champions League and later competing in the FIFA Club World Cup. They set an MLS record for average attendance in each of their first five seasons, supported by a passionate fanbase and a 53-member marching band called "Sound Wave." Notable players include all-time top scorer Jordan Morris, U.S. international Clint Dempsey, and long-time captain Osvaldo Alonso, while the club is majority-owned by Adrian Hanauer and also operates a sister team, Seattle Reign FC, and a lower-division affiliate, Tacoma Defiance.