The prime minister is expected to hold talks with other leaders as a hive of diplomatic activity is expected to play out on the sidelines of the historic event.
Since arriving in Rome on Friday, Mr Albanese has met with Sydney Archbishop Anthony Fisher and Melbourne Archbishop Peter Comensoli, Nine newspapers reported.
The prime minister also spoke briefly about the importance of the inauguration mass for Australia's five million Catholics at a church in Rome that welcomes visiting Australians.
It's a whirlwind two-and-a-half day visit and one the recently re-elected prime minister will be sure to utilise in advancing Australia's domestic and foreign policy agenda.
"It will be an opportunity to have bilateral discussions with a range of world leaders who will be there, people I haven't met before face-to-face," he told reporters earlier this week.
Although official itineraries have not been released publicly, Mr Albanese is expected to meet with Canadian Prime Minister Mark Carney and European Union chief Ursula von der Leyen.
On top of the agenda for both of these meetings will be trade and the war in Ukraine.
Both Canada and the EU have felt the brunt of US President Donald Trump's so-called "Liberation Day" tariffs, and Mr Albanese will be keen to discuss how countries like Australia, Canada or those in Europe can push back on his agenda, protect free trade and preserve elements of the world trading system without unnecessarily aggravating Mr Trump.Â
Mr Albanese will also attempt to revive free trade negotiations with the EU, which broke down in 2023.
Other notable attendees include Ukrainian President Volodymyr Zelenskiy, US Vice President JD Vance, who is set to represent the United States in place of Mr Trump, and Britain's Prince William.
The mass, expected to be attended by tens of thousands of people in St Peter's Square, will begin at 10am local time (6pm on Sunday AEST). It is expected to follow a visit by the Pope to St Peter's tomb in the basilica.
Church leaders will then present the Pope with the pallium, a vestment that signifies his assumption of the papacy, and a fisherman's ring, the symbol of the first apostles being "fishers of men" in the gospels.
It's expected Mr Albanese will formally invite the Pope to Australia for the International Eucharist Conference, which will take place in 2028.
The prime minister, who is also Catholic, said while he often doesn't talk about his religious views, it had informed his morals in politics.
Describing his attendance on Sunday as a "great honour," Mr Albanese also said it would be a historic occasion for the Catholic Church.
"The event will connect Catholics around the world, and the millions of Australians of Catholic faith, as they celebrate and welcome the new Bishop of Rome and pontiff to amplify his message of peace and social justice for all humanity," he said in a statement released earlier in the week.
"I look forward to reinforcing Australia's strong relationship with the Holy See under Pope Leo XIV's pontificate."
7°C