The Diocese was established by papal brief in 1887. Formerly part of Wellington Archdiocese, it embraces the whole of Canterbury and most of Westland in the South Island, as well as the Chatham Islands, the first place in the world to be touched by the sun each day.
Since 1887 the Diocese has had nine bishops. The present Ordinary is Barry Philip Jones, and the Bishop Emeritus John Basil Meeking. The mother church of the Diocese is the Cathedral of the Blessed Sacrament, Christchurch, which in 2005 celebrated its centenary.
Presently, the Diocese has 45 parishes served by secular clergy and priests of the Society of Mary. In addition there are 8 Religious Congregations of women and 4 Congregations of men engaged in pastoral works of various kinds. The Catholic population of the Diocese is 62,715. The diocese covers 51,780 square kilometres (or 20,000 square miles).
The diocesan patron saint is St John the Baptist.
Bishops that have served the Christchurch Diocese are:
- John Joseph Grimes S. M.: 26 July 1887 to 15 March 1915
- Matthew Joseph Brodie: 27 February 1916 to 11 October 1943
- Patrick Francis Lyons: 2 July 1944 to 3 June 1950
- Edward Michael Joyce: 16 July 1950 to 28 January 1964
- Brian Patrick Ashby: 5 August 1964 to 4 July 1985
- Denis William Hanrahan: 4 July 1985 to 1 February 1987
- John Basil Meeking: 3 June 1987 to 15 December 1995
- John Jerome Cunneen: 15 December 1995 to 5 May 2007
- Barry Philip Jones: 5 May 2007