Associazione Calcio Monza (Italian pronunciation: [ˈmontsa] ), or simply Monza, is a professional football club based in Monza, Lombardy, Italy. The team plays in the Serie B, the second tier of Italian football, following relegation in the 2024–25 Serie A season.

The club was founded in 1912 as Monza FBC and came close to promotion to the Serie A on multiple occasions in the 1970s. However, they faced financial issues at times during the first two decades of the 21st century, being declared bankrupt twice, in 2004 and 2015. Following Silvio Berlusconi's takeover of the club in 2018, Monza returned to the Serie B in 2020 after a 19-year absence and achieved promotion to the Serie A for the first time in 2022. Before their promotion, no Italian team had played more Serie B seasons (40) without reaching the Serie A. Monza have won the Coppa Italia Serie C a record four times, the Serie C championship four times, and an Anglo-Italian Cup.

From the club's founding, Monza's colours were blue and white, but they were changed to red and white in 1932. As a result, the team are nicknamed i biancorossi (the white and reds). Monza have played their home games at the Stadio Brianteo since 1988. The team have rivalries with Como, Pro Sesto and Pisa.