[4] The 2016 edition of the MLS Cup was the first to feature two expansion teams not part of the original clubs from the league's inception, with Toronto joining in 2007 and Seattle in 2009.

[8] Toronto FC became the first Canadian club to qualify for the MLS Cup final, in their tenth season in Major League Soccer.

[11] During the 2015–2016 offseason, Toronto acquired a new set of defensive players, including goalkeeper Clint Irwin, midfielder Will Johnson, and defenders Steven Beitashour and Drew Moor.

[12] The team started their first eight matches on the road as BMO Field had not finished renovation work, earning three wins and two draws and staying in a playoff position.

Toronto slumped in May with a string of losses and draws, due in part to injuries to Altidore, Bradley, and Giovinco,[13] but regained form in June with the reopening of BMO Field, capped off with a clinch of the Canadian Championship.

[14] Toronto lost only two of its final fifteen games, stretching from July to October, and qualified for the playoffs as the third seed in the Eastern Conference.

[15] Toronto hosted the Philadelphia Union in the single-match knockout round, winning 3–1 and advancing to a series against New York City FC.

Toronto won the home leg 2–0, and then proceeded to win 5–0 in New York City, setting a record for largest margin of victory on aggregate.

[16] In the Eastern Conference final, Toronto would face their rival Montreal Impact in a bid to be the first Canadian team to play in the MLS Cup.

[17] During the first leg, played in front of a record crowd of 61,004 in Montreal and delayed 41 minutes due to mistakes in the field markings, the Impact took a 3–0 lead shortly after halftime.

While they had won the Lamar Hunt U.S. Open Cup four times and the Supporters' Shield once, the Sounders never advanced further than the Western Conference Finals, which they reached on two previous occasions.

[9][22] The Sounders finished the 2015 season with a loss in the conference semifinals to FC Dallas and plans to retool their roster while chasing the "elusive" MLS Cup.

[24] The team also lost several key players, including star forward Obafemi Martins two weeks before the start of the regular season.

Manager Sigi Schmid left the club on July 26, and was replaced on an interim basis by assistant coach Brian Schmetzer.

[46] The match kicked off at 8:16 p.m. Eastern Time at BMO Field in Toronto, Ontario, Canada, where the ground temperature was reported as −5 °C (23 °F) and estimated at −12 °C (10 °F) with wind chill.

The rest of the half saw missed passes and touches from Toronto, along with a steadfast Seattle defense that let the match head into extra time at 0–0.

[52] The second half of extra time drew to a close after more than 120 minutes of play, with Seattle failing to register a single shot on goal.

[50][53] MLS Cup Most Valuable Player: Stefan Frei (Seattle Sounders FC) Assistant referees: Frank Anderson (United States) Joe Fletcher (Canada) Fourth official: Allen Chapman (United States) Fifth official: Danny Thornberry (United States) Match rules: Seattle Sounders FC became the first MLS club to not register a shot on goal during regular play, surpassing the record of one shot on goal the club set earlier in the season against Sporting Kansas City.