A Vatican communiqué issued on Thursday said the nuncio will shortly be moving to Albania, but did not say anything about his likely successor.
Archbishop Brown’s appointment by Pope Benedict in November 2011 followed the publication of four reports into clerical child sex abuse.
Primate of All Ireland Archbishop Eamon Martin praised the nuncio’s “energy, courtesy, openness, warmth and cooperativeness” and said he had “endeared himself to so many people in Ireland”.
He had travelled “the length and breadth of the island, serving Pope Francis and previously Pope Benedict as the representative of the Holy See”.
“Thanks to his down to earth and friendly nature, many Irish people have had the opportunity to meet with the ‘Pope’s ambassador’ and chat to him about the living Church in Ireland. I know that he has very much appreciated and valued this interaction,” Archbishop Martin said.
Bishop of Elphin Kevin Doran said Archbishop Brown “came among us as a diplomat, at a time when diplomacy was really needed, but he came with the heart of a pastor”.
Bishop Doran noted that Archbishop Brown had to devote “a significant amount of energy to the renewal of the Episcopal Conference”.
In the past five years, 11 episcopal appointments (to the rank of bishop) have been made in Ireland and the process is under way for seven more.
Last August, a group which claims to represent almost a third of Ireland’s Catholic priests severely criticised Archbishop Brown over his selection of bishops.
It just stopped short of asking for him to be replaced.
The Association of Catholic Priests (ACP) said it was “reluctant to call for Archbishop Brown’s removal” but felt it “instructive that his appointment was a central part of Rome’s response to the problems of the Irish Church”.
The policies he pursued in choosing bishops were, “in the main, inadequate to the needs of our time, at odds with the expectations of people and priests and out of sync with the new church dispensation ushered in by the election of Pope Francis”, the ACP said.
It expressed “grave disquiet” at the “lack of consultation” involved, as well as a “preference for candidates drawn from a particular mind-set”.
In September 2013, the same organisation criticised Archbishop Brown, claiming he had been “catapulted out of the Congregation for the Doctrine of the Faith into the diplomatic service by Pope Benedict, as Rome’s answer to the dysfunctional Irish Catholic Church”.
Archbishop Brown was born in New York in 1959 and his mother was Patricia Murphy.
He told the Catholic Herald shortly after his appointment that he was “thunderstruck and flabbergasted” when Cardinal Bertone [the Vatican Secretary of State] presented him with his new mission to Ireland.
On that appointment, he was raised to the level of archbishop and given the titular see of Aquileia.
His only experience of Ireland prior to his appointment came via two short holidays in the early 1980s when, while studying theology at Oxford, he took the Holyhead boat to Dublin to visit a US friend and his Irish girlfriend for Christmas.