Associazione Calcio Monza ([ˈmontsa] (listen)) is a professional football club that is based in Monza, Lombardy, Italy. The team plays in the Serie A, the first tier of Italian football, following promotion in the 2021–22 Serie B season.

The club was founded in 1912 as Monza F.B.C. and on multiple occasions in the 1970s came close to promotion to the Serie A. At times during the first two decades of the 21st century, they faced financial issues; they were declared bankrupt twice, in 2004 and 2015. Following Silvio Berlusconi's 2018 takeover of the club, Monza returned to the Serie B in 2020 after a 19-year absence and reached promotion to Serie A for the first time in 2022. Before their promotion, no Italian team had played more Serie B seasons (40) without playing in 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 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.