Pope Francis has chosen a Melbourne bishop for the College of Cardinals, marking the first time since the death of George Pell that there has been an Australian-based cardinal.

On Sunday, Pope Francis announced 21 new cardinals, including Bishop Mykola Bychok of the Ukrainian Greek Catholic Church, who is based in Melbourne.

Bishop Bychok, who is Ukrainian, relocated to Australia in 2020 after he was appointed as a Bishop by Pope Francis.

He will officially become a cardinal later this year after the Pope announced on Sunday he would hold a consistory for the creation of new cardinals on December 8.

The consistory will expand the College of Cardinals to 256, of which 141 will be cardinal electors who are eligible to vote in a conclave to elect a new pope.

Cardinals over the age of 80 are not eligible to vote in a conclave.

At 44, Bishop Bychok is the youngest of the 21 cardinal-elects announced by Pope Francis.

He will be the first Australian-based cardinal since the death of George Pell in January 2023.

Pell was appointed to the College of Cardinals in 2003.

Announcing the new cardinals on Sunday in Rome, Pope Francis said they were a diverse group.

"Their origins expresses the universality of the Church, which continues to proclaim God's merciful love to all people on earth," he said.

"Their inclusion in the Diocese of Rome also manifests the inseparable bond between the See of Peter and the particular Churches spread throughout the world."

The Ukrainian Catholic Church of Australia, New Zealand and Oceania welcomed the appointment of Bishop Bychok.

"This is a significant event for the entire Ukrainian Greek Catholic Church and the Ukrainian people," it said.

"Therefore, on behalf of all the clergy and faithful of the Eparchy of Melbourne, we sincerely congratulate Bishop Mykola on his proclamation as a cardinal."