The former head of family holding company Edizione which controls Italy's biggest infrastructure group Atlantia, died after a short illness, the family said on Monday.
With his brothers Luciano and Carlo and sister Giuliana, Gilberto founded United Colors of Benetton in a small town in northeast Italy in 1965. Carlo died earlier this year.
The retailer rose to fame in the 1980s and 1990s with its brightly coloured sweaters but faced headwinds in recent times as demand for its products fell.
Besides Atlantia, the Benettons, one of Italy's richest families, also control travel caterer Autogrill and Rome's airports.
As the only member of the family on the Atlantia board, Gilberto faced a major crisis when a bridge in Genoa operated by a unit of Atlantia collapsed in August, killing 43 people.
Earlier this year Atlantia agreed a deal with Spanish builder ACS to take control of motorway group Abertis.
In a statement, the chairman of Atlantia, Fabio Cerchiai, and CEO Giovanni Castellucci said they shared the family's pain at Gilberto's death.
(Reporting by Riccardo Bastianello, Paola Arosio and Stefano Bernabei, writing by Stephen Jewkes; Editing by Adrian Croft and Robin Pomeroy)