Vialli was diagnosed with pancreatic cancer in 2017 but after saying in April 2020 that he had been given the all-clear, he was re-diagnosed in 2021.
He announced a temporary leave from his role with Italy’s national team in December to focus on his health.
The FIGC confirmed that a minute’s silence in memory of Vialli will be held before all Italian matches this weekend.
Vialli played 59 times for Italy, making his debut in 1985, a year after joining Sampdoria where he would win the Serie A title and European Cup Winners’ Cup during eight seasons with the club.
Sampdoria said in a statement: “We won’t forget your 141 goals , your overhead kicks, your cashmere shirts, your earring, your platinum blonde hair, your Ultras bomber jacket. You gave us so much, we gave you so much: yes, it was love, reciprocal, infinite. A love that will not die today with you.”
Vialli helped Sampdoria reach the 1992 European Cup final but after losing to Ajax, he moved to Juventus for a then world record fee of £12m. Vialli spent four seasons with Juve, winning the Champions League, Uefa Cup and Serie A titles.
A Juve statement said: “We loved everything about you, absolutely everything – your smile, your being a star and leader at the same time, on the pitch and in the dressing room, your adorable swashbuckling ways, your culture, your class, which you showed until the last day in the black and white stripes.”
Vialli joined Chelsea on a free transfer in 1996 and became player-manager in 1998 – the first Italian to manage a Premier League side, taking over from the sacked Ruud Gullit late in the season – and went on to lead the Blues to victory in the League Cup, Uefa Cup Winners’ Cup and Uefa Super Cup.
He also guided Chelsea to victory in the 2000 FA Cup final and Charity Shield but was sacked early in the following season after a poor start.
The Blues tweeted: “You’ll be missed by so many. A legend to us and to all of football. Rest in peace, Gianluca Vialli.”
Vialli then had a short spell as manager of Watford, then in the second tier, during the 2001-02 season but was dismissed after the Hornets only finished 14th.
In October 2019 he was appointed to Italy’s backroom staff by manager and former Sampdoria team-mate Roberto Mancini. He helped the Azzurri win Euro 2020 with victory over England at Wembley in July 2021.