Mr Andreotti was taken to hospital last year with heart problems stemming from a respiratory infection.
At his prime, Mr Andreotti was one of Italy’s most powerful men.
He helped draft the country’s constitution after the Second World War, sat in parliament for 60 years and served as prime minister seven times. He remained a senator-for-life.
The Christian Democrat was accused of exchanging a “kiss of honour” with the Mafia’s long-time No 1 boss and indicted in what was called “the trial of the century” in Palermo in the mid-1990s.
He denied any wrongdoing and was eventually cleared by Italy’s highest court.
Rome Mayor Gianni Alemanno called Mr Andreotti “the most representative politician” Italy had known in its recent history.
Mr Andreotti was as known for his political acumen as for his subtle humour and witty allusions. With sharp eyes, thin lips and a stooped figure, he was immediately recognisable to generations of Italians. Friends and foes alike admired his intellectual agility and grasp of the issues.
“Power wears out ... those who don’t have it,” he once famously said.
Mr Andreotti’s rise in the Italian political scene mirrored the rise of Italy, which was then emerging from two decades of Fascist dictatorship under Benito Mussolini. He joined the conservative Christian Democrats, was part of the Constituent Assembly that wrote the constitution and was elected to parliament in 1948.
He remained ever since.
He held a series of Cabinet positions after the war, until he became premier for the first time in 1972. Twenty years later, he finished his last stint.
Although staunchly pro-American and a firm supporter of Italy’s Nato membership, Mr Andreotti was the first Christian Democrat to accept Communist support, even if indirect, in one of his governments.