Associazione Calcio Milan (Italian pronunciation: [assotʃatˈtsjoːne ˈkaltʃo ˈmiːlan]), commonly referred to as Milan or AC Milan (Italian pronunciation: [a tˌtʃi mˈmiːlan]) mainly outside of Italy, is an Italian professional football club based in Milan, Lombardy. Founded in 1899, the club competes in the Serie A, the top tier of Italian football. In its early history, Milan played its home games in different grounds around the city before moving to its current stadium, the San Siro, in 1926. The stadium, which was built by Milan's second chairman, Piero Pirelli, and has been shared with Inter Milan since 1947, is the largest in Italian football, with a total capacity of 75,817. The club has a long-standing rivalry with Inter, with whom they contest the Derby della Madonnina, one of the most followed derbies in football.

Milan has spent its entire history in Serie A with the exception of the 1980–81 and 1982–83 seasons. Silvio Berlusconi’s 31-year tenure as Milan president was a standout period in the club's history, as they established themselves as one of Europe's most dominant and successful clubs. Milan won 29 trophies during his tenure, securing multiple Serie A and UEFA Champions League titles. During the 1991–92 season, the club notably achieved the feat of being the first team to win the Serie A title without losing a single game. Milan is home to multiple Ballon d'Or winners, and three of the club's players, Marco van Basten, Ruud Gullit, and Frank Rijkaard, were ranked in the top three on the podium for the 1988 Ballon d'Or, an unprecedented achievement in the history of the prize.

Milan is one of the most successful football clubs in the world in terms of total trophies won. Domestically, Milan has won 19 league titles, 5 Coppa Italia titles and 8 Supercoppa Italiana titles. In international competitions, Milan is Italy's most successful club. The club has won seven European Cup/Champions League titles, making them the competition's second-most successful team behind Real Madrid, and further honours include five UEFA Super Cups, two UEFA Cup Winners' Cups, a joint record two Latin Cups, a joint record three Intercontinental Cups and one FIFA Club World Cup.

Milan is one of the wealthiest clubs in Italian and world football. It was a founding member of the now-defunct G-14 group of Europe's leading football clubs as well as its replacement, the European Club Association.