Bishop of Christchurch On 5 December 2017, Martin was appointed by
Pope Francis to replace
Barry Jones, the 9th bishop of Christchurch, who died on 13 February 2016. On 3 March 2018 he was consecrated as the 10th bishop of Christchurch, in a large gathering at
Boy's High School Auditorium, Christchurch, by
Cardinal John Dew, Archbishop of Wellington, bishop emeritus of Christchurch
Basil Meeking and
Charles Drennan of
Palmerston North. During his tenure as
Bishop of Christchurch, the diocese saw restructuring of parishes. Many parishes were combined to create five 'super' parishes in Christchurch, as well as combining all churches in the
Selwyn and
Waimakariri Districts in their own parish. One of the decisions he faced as Bishop of Christchurch was the future of the
Cathedral of the Blessed Sacrament, after it was severely damaged in the
2010,
February 2011 and
June 2011 Canterbury earthquakes. His predecessor, Barry Jones had suggested that the
nave of the cathedral could be saved. In August 2019, Martin made the decision to demolish the cathedral. By September 2020, the demolition work began. In December 2019, Martin made public plans for a new cathedral site, Catholic primary school, hotels, offices and a carpark, all in community and commercial collaboration with Ōtākaro Limited, and city developers, Carter Group.
Archbishop of Wellington On 1 January 2021, he was appointed coadjutor Archbishop of the Archdiocese of Wellington by Pope Francis. He succeeded to the see on 4 May 2023 on his predecessor,
Archbishop Dew attaining the age of 75 and his resignation being accepted by Pope Francis. He was installed as archbishop at
St Theresa's Pro-Cathedral, Karori on 17 June 2023. ==The 2024 Royal Commission of Inquiry into Abuse in Care==