Broz, who was married to Tito for nearly 30 years, died in a hospital today of heart failure, said Zlatibor Loncar, head of Belgrade's emergency hospital.
Broz had been hospitalised since late August.
Tito, whose Partisan guerrilla fighters fought against German Nazi occupiers during World War II, took power in Yugoslavia after the war ended.
He ruled the multiethnic federation with a heavy hand until his death in 1980.
Tito's successors later stripped Broz of her rights, placing her in virtual house arrest.