He was appointed bishop by Pope Benedict XVI on 11 April 2011. He received his secondary education at Street Patrick"s College, Silverstream. After ordination, Donoghue taught for some time at Street Bede"s College, Christchurch, before joining the Marist Oceania province.
When he was appointed as Bishop of Rarotonga he was the Provincial Superior of the Oceania province (2006-2011).
Prior to being provincial he taught at Chanel College, Moamoa (1977-1981), Samoa, and was Marist novice master at the Marist Training Centre, Tutu, Taveuni Island (1985-1990), Fiji. He was director of the Street Martin de Porres Centre, Lololima, Malekula Island, Vanuatu (1993-1996) and regional superior, Vanuatu (1996-1998).
He returned to Tutu and was formator of novices there (1998-2000). From 2000 to 2006 he participated in the Marist renewal programme in Ireland.
Donoghue was consecrated a bishop on 16 July 2011 with Principal Consecrator being his immediate predecessor, Bishop Stuart France O’Connell, South.M and the Principal Company-Consecrators were Archbishop Charles Daniel Balvo (Nuncio to the Cook Islands) and Bishop Denis George Browne of Hamilton (also a predecessor in Rarotonga).