Sergio Castelletti (; 30 December 1937 â 28 November 2004) was an Italian professional footballer and manager, who played as a defender.
As a footballer, he played several seasons with Fiorentina, winning twice Coppa Italia (1961, 1966), a UEFA Cup Winners' Cup (1961) and a Mitropa Cup (1966).
Along with his team-mate Enzo Robotti, who also came from the province of Alessandria like Castelletti himself, he formed a strong full-back pairing, which sometimes even lined up with the Italy national football team.
After the end of his playing career, Castelletti trained Fiorentina youth team, some clubs in Serie B and in lower divisions.
He died in 2004.