Bishops are appointed by the Holy Father. The pastoral care of a diocese is entrusted to a diocesan bishop (sometimes referred to as the Ordinary of the diocese). An auxiliary bishop assists the diocesan bishop. A coadjutor bishop has the right to succeed the diocesan bishop as Ordinary of the diocese.
Several neighbouring dioceses may constitute an ecclesiastical province, which is presided over by a bishop who is called the metropolitan. A metropolitan is an archbishop, and the bishops of other dioceses in the province are called suffragan bishops.
Bishops normally offer their resignation to the Holy Father when they reach the age of 75. When their resignation is accepted they become an emeritus archbishop or bishop. There are currently six diocesan bishops, six emeritus bishops, and an emeritus archbishop in New Zealand.
| Cardinal Thomas Williams | Archbishop Emeritus of Wellington |
| Most Reverend Leonard Boyle | Emeritus Bishop of Dunedin |
| Most Reverend Owen Dolan | Emeritus Coadjutor Bishop of Palmerston North |
| Most Reverend Peter Cullinane | Emeritus Bishop of Palmerston North |
| Most Reverend Robin Leamy SM | Emeritus Bishop of Rarotonga |
| Most Reverend John Mackey | Emeritus Bishop of Auckland |
| Most Reverend Basil Meeking | Emeritus Bishop of Christchurch |
| Most Reverend Charles Daniel Balvo |
Apostolic Nuncio |