Due to the ongoing COVID-19 pandemic, the season was originally scheduled to begin on April 3, as opposed to the normal late February or early March start.

The New England Revolution won their first Supporters' Shield, in the process breaking the record for most regular season points collected.

[4] New York City FC won their first ever MLS Cup, beating Portland Timbers in the decider.

[29][30] On July 14, MLS announced that both CF Montreal and Toronto FC planned to return to playing matches at their home stadiums beginning July 17, citing new policies allowing vaccinated individuals to enter the country without 14 days self-isolation, provided that they test negative on a COVID-19 test.

[30][31] However, Sportsnet reported that the plans had not yet been formally approved by the Public Health Agency of Canada, and that the Canadian government was expected to issue a statement on the matter.