Baresi spent his entire club career at AC Milan in Italy. During his 20 years at the club, 15 of them as captain, he made 719 appearances and won six league titles. He also won three Champions League titles, previously the European Cup.
After his playing career, he coached youth teams at Milan, and then became vice-president of the club.
"Announcing the loss of someone who embodied Milan's heart and soul is incredibly tough," Milan wrote in a statement.
Baresi made 81 appearances for the Italian national team, and was part of the team that won the World Cup in 1982.
The former centre-back underwent surgery for a lung nodule in 2025, and has had health problems throughout the year, according to Gazzetta dello Sport.
Baresi was 66 years old.
