As well as serving as president from 1999 to 2006, Ciampi was prime minister of a caretaker
government of technocrats from 1993 to 1994. As treasury minister in the late 1990s he played an important role in Italy's adoption of the euro as its currency.
The news was broken by Italy's current prime minister, Matteo Renzi, who tweeted his government's condolences to Ciampi's widow, and paid tribute to the former head of state:
"A thought of gratitude goes to a man of the institutions, who served Italy with passion", he said.
L'abbraccio del Governo alla signora Franca. E un pensiero grato all'uomo delle Istituzioni che ha servito con passione l'Italia #Ciampi— Matteo Renzi (@matteorenzi) September 16, 2016
As president, Ciampi was so popular that he was widely urged to serve a second term – a proposal he declined on the grounds of his advanced age.
Ciampi spent 14 years as governor of the Bank of Italy and later served as a treasury minister, a role in which he was the principal architect of Italy's adoption of the euro as one of the founder members of the single currency.
Foreign Minister Paolo Gentiloni hailed "a great Italian statesman," and other tributes poured in from across the political spectrum.
A career economist, Ciampi was politically on the centre-left although he was not officially aligned to any party for the bulk of his career.
He took over as prime minister at a time when Italy was reeling from the enormous "mani pulite" (clean hands) corruption scandal.
As president, a largely ceremonial role in Italy, he was credited with being a restraining influence on Silvio Berlusconi when the controversial media tycoon was prime minister.
Ciampi leaves a widow, Franca, to whom he was married for 70 years, and two children. Media reports said he had died after spending several weeks in a Rome hospital.