The sensitive tax fraud case, which began seven years ago, revolves around television distribution rights bought by the billionaire tycoon's media empire Mediaset.
The result of the hearings risks upsetting Italy's fragile right-left coalition government.
The Supreme Court hearing is expected to start at 0800 GMT in Rome but Italian media reported that the actual verdict may come only on Wednesday.
There is even a possibility that the case could be adjourned to September. The court is ruling on Berlusconi's second and final appeal against his conviction, a verdict that could effectively end the flamboyant politician's parliamentary career.
That would mark a milestone in the history of the legal woes and sex scandals that have dogged his 20 years on the Italian political scene.
In other court cases, Berlusconi has also been convicted of having sex with an underage prostitute, abusing his powers as prime minister when he was in office and publishing a secret police wiretap to damage a political rival.
He denies all charges and is appealing against those rulings, accusing prosecutors of being politically biased and pursuing a vendetta against him.
Even if the court upholds Berlusconi's tax fraud conviction, the Senate would still have to vote to allow the sentence to be implemented since Berlusconi has a seat in the upper house.
The process could take several months if Berlusconi loyalists employ stalling tactics.
Legal experts say there is virtually no chance of Berlusconi being sent to prison because of lenient sentencing guidelines for over-70s in Italy. There is however a possibility that the three-time prime minister could be put under house arrest.
A political ban would also eject the 76-year-old from the Senate and prevent him from running for office for five years. He would however remain in the political arena as a figurehead leader of his centre-right People of Freedom party.
The court could also acquit Berlusconi entirely or send the case back to the appeal courts for another trial. But if that happened, say experts, the trial would probably have to be scrapped with no verdict because all the charges expire under a statute of limitations next year.
In an interview published on Sunday by the newspaper Libero, Berlusconi sounded nervous but bullish about his chances.
"I am quite optimistic, they cannot find me guilty. I was the prime minister (at the time of the alleged crime), what could I possibly have known about contracts for television rights?" he said.
"I haven't slept for a month. I wake up at night and stare at the ceiling, thinking about what they've done to me," he added.
He also emphasised that he would "not go into exile" like one of his predecessors and political mentors, Bettino Craxi, who fled to Hammamet in Tunisia and was convicted of corruption in the early 1990s.
Berlusconi has said he does not want the ruling to have an impact on the government, a coalition forged after two months of political stalemate following February elections. Some of his diehard supporters however have taken a harder line.
Many analysts dismissed Berlusconi when he was ousted from power at the end of 2011 by a parliamentary revolt and a wave of panic on the financial markets.
But he staged an impressive comeback in this year's general election, with his coalition coming an extremely close second to the main centre-left grouping with nearly a third of the vote.