Her death is being mourned by royalists in Italy, who have planned memorial services at the Pantheon in Rome, the traditional resting place of Italian monarchs.
She had suffered lung problems at a Geneva clinic for some time, but a family spokeswoman who confirmed her death, on Saturday, did not give the precise cause.
However less than a month later, Umberto left the country amid growing anti-monarchist feeling due to the royal family's support for Benito Mussolini's fascist regime during the war.
In 1948, the newly-formed republic's constitution barred Umberto and his male descendants from Italy.
The ban remains in force despite protests and legal challenges from the exiled crown prince Victor Emmanuel.
Royalists mourn
In a brief appearance on Italian television, Victor Emmanuel's wife, Marina Doria, said the late former queen will be buried next week at Hautecombe Abbey in France.
Her death is being mourned by royalists in Italy, who have planned memorial services at the Pantheon in Rome, the traditional resting place of Italian monarchs.
Sergio Boschiero, the head of a leading royalist association, said her death "saddens not only monarchists, but innumerable Italians who recall her regality and her love of liberty and the people."
Royalists are "hoping that one day all the bodies of the other Italian sovereigns now buried in foreign soil will be laid to rest here together," he added.
Exiled dynasty
A constitutional amendment allowing the Savoys to return to Italy was approved by the lower house of parliament in 1998, but has since been bogged down in a Senate committee.
Last year, the European Parliament voted down a proposal that Italy should end the 54-year exile as "a cruel and unusual punishment with no place in a modern Europe".
Members of the ousted dynasty spent their exile in a lakeside village on the outskirts of Geneva, where Umberto died in 1983.