The government is honoring Iloilo with a full state funeral Thursday, and national flags on all government buildings will stay at half staff until the funeral ends. He had a longtime heart condition, and the government said he died Feb. 7 at Suva Private Hospital.
A traditional high chief and former teacher, Iloilo became a key ally of armed forces chief Commodore Frank Bainimarama who overthrew the elected government in a December 2006 coup amid rising tensions between indigenous Fijians and the country's large ethnic Indian minority.
Bainimarama seized the president's powers in the coup, but returned them within days to Iloilo, who then swore in the armed forces chief as prime minister and his appointees as the Cabinet, giving the regime a veneer of legitimacy.
Iloilo stepped in again on Bainimarama's behalf in April 2009, when Fiji's Court of Appeal ruled that Bainimarama's government was illegal and all decisions that it had made were invalid.
Iloilo responded by abolishing the constitution, firing the nation's judges and imposing emergency rule that continues to this day, with the nation ruled by decrees issued by the office of president on the advice of Bainimarama and his Cabinet.
Since the coup - Fiji's fourth since 1987 - Fiji has been suspended from the 53-nation Commonwealth group and 16-country Pacific Islands Forum, and aid from the Commonwealth and European Union has been cut. Neighbors Australia and New Zealand have imposed travel sanctions on its leadership.
But Bainimarama has refused to bow to demands for an early return to democracy, saying he will reform the country's institutions and root out corruption before holding elections in 2014.
Iloilo stood down as president in 2010 and was replaced by Ratu Epeli Nailatikau, a former armed forces commander.
He had been appointed to the country's highest office in 2000, shortly after the collapse of the country's third military coup. He swore in the Cabinet of the democratically elected government of premier Laisenia Qarase that lasted until the 2006 coup.
On Tuesday, Bainimarama, Nailatikau, armed forces units and a military band marched through the streets of the capital, Suva, accompanying a gun carriage that bore Iloilo's casket.
Thousands crowded the route through city streets to pay respects to Iloilo as army units in full ceremonial dress marched to the solemn beat of drums.
His widow, Adi Kavu Seniloli, rode in the official vehicle that followed the gun carriage.
Iloilo will be interned at his tribal village of Viseisei on Thursday.