List of Seattle Sounders FC seasons

Seattle Sounders FC is a soccer team based in Seattle, Washington, that competes in Major League Soccer (MLS), the most senior soccer league in the United States. The club was established in 2007 as an MLS expansion team, succeeding an existing second-division team of the same name, and began play in 2009. The MLS regular season typically runs from February to October and the best-performing team is awarded the Supporters' Shield; the top nine teams from each conference qualify for the MLS Cup Playoffs, a postseason tournament that culminates in the MLS Cup.

In addition to league play, the Sounders compete in the annual U.S. Open Cup tournament organized by the United States Soccer Federation and the Leagues Cup contested by teams from MLS and Liga MX of Mexico. The league and cup tournaments serve as qualifiers for the following year's CONCACAF Champions Cup (formerly the CONCACAF Champions League), an annual international competition between league and cup champions in North America, Central America, and the Caribbean. The CONCACAF Champions Cup winner then qualifies for the next FIFA Club World Cup, which is held annually but will switch to every four years beginning in 2025.

The Sounders are one of the most successful clubs in MLS history, having won eight trophies since entering the league in 2009. They won three consecutive U.S. Open Cup titles from 2009 to 2011 and a fourth in 2014, becoming the second MLS club to do so. The club earned their first Supporters' Shield in 2014, completing a double, and won the MLS Cup in 2016 and 2019 during a run of four finals in five years. They won the CONCACAF Champions League in 2022, becoming the first MLS club to win the competition under its modern format and qualify for the FIFA Club World Cup. The Leagues Cup remains the only major North American competition that the Sounders have not won; the team finished as runners-up in the 2021 edition. Sigi Schmid was the club's head coach from the inaugural MLS season in 2009 until July 2016; he was replaced by Brian Schmetzer, initially as interim coach and later as full head coach. Colombian striker Fredy Montero is the club's all-time top scorer with 76 goals; he joined the club in 2009 and has played for the Sounders in two stints.

As of the end of the 2022 season, the club has played 14 seasons in MLS with 211 wins, 141 losses, and 104 draws—a winning percentage of 0.577. The Sounders qualified for the MLS Cup Playoffs in their first 13 seasons—as of 2022^[update], they were tied for the MLS record and the second longest among the major sports leagues in the United States behind the National Hockey League's Pittsburgh Penguins. The Sounders led MLS attendance in their first eight years in the league, averaging over 30,000 per season, until they were surpassed by Atlanta United FC in 2017. The club achieved their highest season attendance in 2015 with 44,247 per match; as of 2022, the 219 regular season matches at Lumen Field in Seattle have averaged 39,053 spectators and drawn over 8.55 million total people. The most-attended home Sounders matches were the 2022 CONCACAF Champions League Final's 2nd leg with 68,741—a tournament record—and MLS Cup 2019 with 69,274 spectators.