Rossi's wife Federica Cappelletti announced the death with a post on Instagram alongside a photo of the couple, accompanied by the comment "Forever," followed by a heart.
"There will never be anyone like you, unique, special, after you the absolute nothing....," Cappelletti also wrote on Facebook.
The cause of his death was not revealed but Italian media reported that Rossi had been suffering from "an uncurable disease".
Tributes were paid to 'Pablito', the star who was banned for three years for his part in a betting scandal, but returned to win the World Cup in Spain and the Ballon D'Or the same year.
Despite breaking in the early hours, Italian media splashed with the news, while social media lit up with tributes and "Paolo Rossi" was Italy's number one trending search item.
"Football and Italy mourns Paolo Rossi," headlined the Gazzetta dello Sport, as La Stampa called him the "hero of Spain '82".
The news of his passing comes two weeks after the death of Argentina football legend Diego Maradona, winner of the 1986 World Cup.
Rossi won the hearts of Italian fans during the summer of 1982, when his goals dragged Enzo Bearzot's Azzurri to a third world title.
Italy started the tournament with three uninspiring draws before they came to life and marched to the title.
