Cardinal Seán Brady has been presented with his cardinalatial ring by Pope Benedict XVI at a Mass in St Peter's Basilica.
Each of 23 new cardinals elevated at a consistory yesterday received the special ring during the Mass of the Rings today.
Pope Benedict led a solemn ceremony in which he urged the new cardinals to work for peace.
The Pope presided over the ceremony in St Peter's Basilica a day after he elevated the prelates from around the world to the elite rank in the 1.1 billion-member Catholic Church.
As each of the cardinals knelt before him, Benedict slid the ring of office on their finger and, speaking in Latin, told them it should always be a symbol of their love for the Church.
Earlier, in his sermon in front of the central altar of the flower-bedecked basilica, he asked them to work and pray for peace and unity.
"Prayer for peace and unity constitutes your first and principal mission ...," he said.
The new cardinals come from Italy, Iraq, Ireland, Germany, the United States, Spain, India, Argentina, Kenya, Mexico, Poland, Senegal, Brazil and France.
When he elevated them to the new rank yesterday, he appealed for an end to the war in Iraq and decried the plight of the country's Christian minority.
Cardinal Brady will today celebrate Mass in the Lateran Basilica, followed by a reception at the Pontifical Irish College.
His Eminence will fly home on Thursday morning to Dublin airport where he will be greeted by the Taoiseach.
On his journey back to Armagh, he plans to visit St Peter's Church and Sienna Convent, Drogheda, Collon Monastery, Ardee, St Patrick's, Dundalk, Newtownhamilton, Keady and Ballymacnab.
The new Cardinal will arrive just outside Armagh at 7pm and board an open-top vehicle to parade through the town.
Mass will be celebrated in St Patrick's Cathedral, Armagh, at 8pm.