Leagues Cup

Major League Soccer and Liga MX clubs had previously played in the North American SuperLiga, which ran from 2007 to 2010. Both leagues also send clubs to the CONCACAF Champions League, which has been dominated by Mexican clubs, and the Campeones Cup, a single match played between the winners of the MLS Cup and the Campeón de Campeones. The two leagues began planning a bi-national, eight-team competition to complement the Champions League and provide Mexican clubs with matches to replace the Copa Libertadores in their calendar as soon as 2018. MLS and Liga MX announced a new partnership in March 2018 to create the Campeones Cup and explore options for other bi-national competitions between their clubs.

The Leagues Cup tournament was announced on May 29, 2019, featuring eight teams in its inaugural edition to be played during the summer. The announcement of the tournament was panned by soccer critics in the United States, who called it a meaningless friendly and "cash-grab" for American clubs. The MLS Players Association also expressed concerns over the tournament's creation on the basis of schedule congestion during the summertime. Sam Boyd Stadium in Whitney, Nevada was later announced as the host venue for the final and a broadcasting contract for the tournament was awarded to ESPN and TUDN (formerly Univision Deportes Network). This event was also televised on TSN and TVA Sports in Canada and Televisa in Mexico.

In July 2019, MLS and Liga MX announced that the second edition of the Leagues Cup in 2020 would feature 16 teams—eight from each league. The MLS participants would be drawn from the top four teams in each conference that do not qualify for the CONCACAF Champions League; the Liga MX participants would include the 2019 Apertura champion, 2020 Clausura champion, the 2019–20 Copa MX champion, and the next five best-placed teams in the 2019-20 season aggregate table the league. The tournament was canceled on May 19, 2020, amid the COVID-19 pandemic. The eight-team format debuted in the 2021 Leagues Cup, which was played in August and September. In the final at Allegiant Stadium in Paradise, Nevada, Mexican club León defeated Seattle Sounders FC, the first American finalist in the competition's history.

On April 14, 2022, MLS and Liga MX announced the 2022 Leagues Cup Showcase, which was held starting August 3, 2022, at SoFi Stadium in Inglewood, California. The event included a doubleheader of matches: LA Galaxy against C.D. Guadalajara and Los Angeles FC against Club América. On June 30, 2022, it was announced that the Leagues Cup Showcase was expanded to include three more matches—FC Cincinnati against C.D. Guadalajara at TQL Stadium in Cincinnati, Ohio; Nashville SC against Club América at Geodis Park in Nashville, Tennessee, on September 21; and Real Salt Lake against Atlas F.C. at Rio Tinto Stadium in Sandy, Utah, on September 22. The events served as a one-time replacement of the previously planned 2022 Leagues Cup which was not held due to fixture congestion from the 2022 FIFA World Cup and other factors.

The Leagues Cup was expanded in 2023 to include all MLS and Liga MX clubs, during a month-long pause in their respective seasons. It also became a qualification tournament for the 2024 CONCACAF Champions Cup with three berths for teams from North America. The Leagues Cup champion qualified directly to the round of 16, while the runner-up and third-place finisher earned round one berths. Inter Miami CF won the first edition of the expanded tournament in 2023, led by top goalscorer Lionel Messi.

On January 28, 2025, Major League Soccer announced that they would only send 18 representatives to the Leagues Cup for 2025 as part of their new competition guidelines, which only allowed teams to play in at most two cup competitions. Most of the teams in the 2024 MLS Cup playoffs qualified for Leagues Cup; the Vancouver Whitecaps, as winners of the 2024 Canadian Championship, had their place forfeited and given to expansion club San Diego FC.

The addition of the Leagues Cup and subsequent schedule congestion led Major League Soccer to announce their intention not to field senior teams in the U.S. Open Cup, the domestic cup competition for the United States. The announcement was met with "widespread anger and condemnation" and the proposal was rejected by the United States Soccer Federation. A hybrid plan with eight MLS participants and MLS Next Pro reserve teams as replacements for the remaining teams was used for the 2024 U.S. Open Cup. Several Major League Soccer supporters' groups have announced boycotts of the Leagues Cup.