Seattle Sounders Football Club is an American professional men’s soccer club based in Seattle. The Sounders compete as a member of the Western Conference of Major League Soccer (MLS). The club was established on November 13, 2007, and began play in 2009 as an MLS expansion team. The Sounders play their home league matches at Lumen Field. The Sounders played their inaugural match on March 19, 2009, winning 3–0 over the New York Red Bulls. Seattle has been among the league’s most successful teams, winning the U.S. Open Cup four times, the Supporters’ Shield in 2014, and the MLS Cup in 2016 and 2019. From its MLS inception until 2022, the team qualified for the MLS Cup Playoffs—the longest record in league history—and competed in the CONCACAF Champions League six times, becoming the first MLS team to win the modern version of the competition in 2022. The Seattle Sounders were the first MLS team to participate in the FIFA Club World Cup. The team set a new MLS record for average attendance in each of its first five seasons. The Sounders are ranked as one of the most valuable franchises in North America.