2020 Major League Soccer season

The 2020 Major League Soccer season was the 25th season of Major League Soccer (MLS), the top professional soccer league in the United States and Canada. The regular season began on February 29, 2020, and was originally planned to end on October 4. The MLS Cup Playoffs were planned to begin later that month and would end with MLS Cup 2020 on November 7.

On March 12, 2020, the season entered a lengthy suspension due to the COVID-19 pandemic in North America, following the cancellation of several matches. On May 1, the league announced that players would be allowed to resume individual outdoor training at MLS facilities on May 6. The COVID-19 pandemic was the first interruption of regular season play since the 2001 MLS season, in which many late regular season games were canceled due to the September 11 attacks. On June 10, MLS announced that a bracket format dubbed the "MLS is Back Tournament" would begin July 8 at ESPN Wide World of Sports Complex in Walt Disney World, and end with the final on August 11. The tournament included 51 matches in 35 days and over 1,000 players and staff quarantined to a set of hotels at Walt Disney World; it was eventually won by the Portland Timbers, who as a result earned a berth in the 2021 CONCACAF Champions League. The regular season later resumed a day after the tournament finished, and concluded on November 8. The playoffs began on November 20 with MLS Cup 2020 now being played on December 12.

The 2020 season saw the addition of two expansion clubs, Inter Miami CF and Nashville SC, which took Major League Soccer to 26 total teams. Nashville SC was initially placed in the Western Conference, for a 13–13 team balance, despite Nashville being to the east of the western most Eastern Conference team, Chicago Fire FC. However, after the MLS Is Back Tournament, COVID-19 difficulties led to MLS limiting teams to matches with teams in geographic proximity, and as a result Nashville was moved to the Eastern conference due to geography. This led to an imbalance, with 14 teams in the Eastern Conference and 12 in the Western Conference. Prior to the COVID-19 pandemic, this season was planned to be the first MLS season in which each team did not play every other team at least once, but, due to the pandemic, the schedule was heavily modified and most teams only played other teams within a regional geographic bubble. During the regular season around September and toward the end of the season, COVID-19 cross-border restrictions imposed by the Canadian government forced the Canadian MLS teams to play home matches in the United States.

The Philadelphia Union won the Supporters' Shield on the final day of the regular season, the first major trophy in the club's history. Columbus Crew SC defeated defending champions Seattle Sounders FC in MLS Cup 2020 3–0 to win a second MLS Cup title, and their first since 2008. The league's teams incurred an estimated financial loss of $1 billion due to lost ticket sales and additional costs. The 2020 season was the longest in MLS season, stretching 287 days.