In Dublin, 53 years of age, he has become the first foreign-born priest who has been bishop of the diocese in more than 300 years.
Father Fintan Gavin, from Marino to Dublin, was ordained bishop of the Cork and Ross diocese at a ceremony in the cathedral in the north of the city this afternoon.
The diocese is the third largest Catholic diocese in the country.
It was the first ordination of a Catholic bishop in Cork since 1984 when Bishop John Buckley was ordained as auxiliary bishop.
With a Catholic population of around 285,000 through 68 parishes, they range from the island of Sherkin to the west of the county, to the urban parishes of the city of Cork, with some 80 priests in active ministry.
Around 1,200 attended the ceremony, including 110 priests, among them Archbishop of Dublin, Dr. Diarmuid Martin and the representative of the representative in Ireland, Archbishop Jude Thaddeus Okolo.
Speaking before the ceremony, the elect bishop said that he knew that he was facing challenges, but added: "I am ready to enter the playing field and take on the mandate of renewal."
The Gospel Heart of the Parish of Our Lady of Victories, Ballymun, was among a series of choirs including the Heart of the Deaf Cork Community to participate in the two-hour ceremony.
The ceremony was broadcast live online for the first time and was also shown on a big screen at St Patrick's Cathedral in Skibbereen.
Father Fintan was Chancellor of the Archdiocese of Dublin and chaplain of the parish of Our Lady of Victories, until his appointment to the Diocese of Cork and Ross.
Church must ask for forgiveness again
The newly appointed bishop said that the Church had to make a petition and apologize again to those who lost their faith or who are fighting for the abuse done in the name of " # 39; church
Speaking this afternoon, Bishop Fintan Gavin said that the Church needs "to extend the hand of dialogue and listen so that their voices are heard, so we can apologize again and learn from the terrible things" # 39; ls allowed to pass.
"We will never be able to allow this to happen again."
The bishop made his comments during his ordination ceremony, attended by more than 1,200 people.
With a spirit of ecumenism, the bells of Cathedral of the Church of Ireland in the city of Cork sounded to accommodate the order of the new Catholic bishop of the city.
He will now supervise the country's third largest Catholic diocese.
In Skibbereen, more than 850 met at St. Patrick's Cathedral to see how the live broadcast on a big screen was transmitted.
The ceremony was also held online for the first time.
Appointed in April by Pope Francis to succeed Bishop John Buckley, Dubliner was Chancellor of the Archdiocese of Dublin and chaplain of the parish of Our Lady of Victories, Ballymun Road.
Speaking at the beginning of the ceremony, Emeritus Bishop of Cork and Ross John Buckley said it was an honor for him to order his successor.
Bishop Gavin also explained the meeting that the Church must find new ways to face the challenges that are facing today.
He must promote more vocations towards the priesthood and reach those who have lost faith or who are fighting.
The parents of Bishop Gavin, as well as his six brothers, were among those attending the ceremony.