Liga MX, officially known as Liga BBVA MX for sponsorship reasons, is the top professional division of Mexican football. Formerly called Liga Mayor (1943–1949) and then Primera División de México (1949–2012), it has 18 clubs and the season is divided into two short tournaments, Apertura from July to December and Clausura from January to May. The champions of each tournament is decided by a final phase called "liguilla". Since 2020, promotion and relegation has been suspended, which is to last until 2026.
The league currently ranks first in CONCACAF's league ranking index. According to the IFFHS, Liga MX was ranked as the 10th strongest league in the first decade of the 21st century. According to CONCACAF, the league – with an average attendance of 25,557 during the 2014–15 season – draws the largest crowds on average of any football league in the Americas and the third largest crowds of any professional sports league in North America, behind only the NFL and MLB. It is also the fourth most attended football league in the world behind Germany's Bundesliga, England's Premier League and Spain's La Liga. Liga MX ranks second in terms of television viewership in the United States, behind the English Premier League.
América have won the league a record of 15 times, followed by Guadalajara with 12 titles, Toluca 10 titles and Cruz Azul 9 titles. In all, twenty-four teams have won the top professional division title at least once.
Prior to the Liga Mayor, there was no national football league in Mexico, and football competitions were held within relatively small geographical regions. The Liga Mexicana de Football Amateur Association, a local league consisting of teams near and around Mexico City, was the first amateur football league created in Mexico, and also other regional leagues were created, which were the Liga Amateur de Veracruz, Liga Amateur de Puebla, Liga Occidental De Jalisco and the Liga Amateur del Bajío that had talented clubs.
In 1922, after the foundation of the first football federation in Mexico, they created the Campeonato de Primera Fuerza, which was the first amateur league organized by a national football federation. It was held from 1922 to 1943, although most of the participating teams were from Mexico City and the first matches held outside the country's capital were played until the 1940–41 season.
Many club owners were keen to remain amateur although they paid players under the table. The increasing interest in football would not thwart a unified professional football system in the country. The first true national and professional league in Mexico was established in 1943.
The Federación Mexicana de Fútbol (FMF) announcement of the nation's first professional league brought interest from many clubs to join. The FMF announced that 10 clubs would form the Liga Mayor. The league was founded by six clubs from the Liga Mexicana de Football Amateur Association, two clubs from the Liga Occidental, and two from the Liga Veracruzana.
Throughout the late 1950s and early 1960s, many small clubs faced economic difficulties which were attributed to the lack of international competition by Mexico's clubs and an unrewarding league format. Consequently, teams from Mexico that placed high in the league standings could not afford to participate in the overarching continental competitions, such as the Copa Libertadores.
The 1970 World Cup held in Mexico was the first World Cup televised on a grand scale. The season following the FIFA World Cup, the FMF changed the league format and established a final phase to determine the national champion. This was done to regenerate interest and reward teams that placed fairly high in the standings.
The final phase, called Liguilla, was played using various formats to determine the champions. The most common format was a straight knock-out between the top eight teams in the table. At other times the league was divided into groups with the top two in each group, often as well as the best 3rd placed teams, qualifying for the liguilla and in some seasons the playoff matches themselves involved teams playing in groups with the group winners playing off for the title. The format was changed from season to season to accommodate international club commitments and the schedule of the Mexico national team.
The change in the rules affected teams that traditionally dominated the table, as talented teams that had not performed well in the regular season were able to perform successfully in the final phase (Cruz Azul in the 1970s, América in the 1980s, and Toluca in the 2000s).
Prior to the start of the 2012–13 season, the organization Liga MX/Ascenso MX was created to replace the FMF as the organizing body of the competition. The league also announced a rebranding, with the introduction of a new logo.
On 20 August 2018, it was announced that Liga MX would begin testing the use of VAR technology. The initial test run will be conducted during under-20 matches played inside senior league stadiums, with live testing across senior Liga MX matches to take place during weeks 13 and 14 of the Apertura tournament. The league will, however, still need final approval from FIFA to fully implement the technology.