The Roman Catholic Diocese of Christchurch is a suffragan diocese of the Archdiocese of Wellington. Its cathedral and see city are located in Christchurch, the largest city in the South Island of New Zealand. It was formed on 5 May 1887 from a portion of the territory of the Diocese of Wellington, which was elevated to archdiocese later that same month.

The Roman Catholic Archdiocese of Wellington is the metropolitan archdiocese of New Zealand. Catholics number about 83,214. Parishes number 22 and the archdiocese extends over central New Zealand between Levin and Masterton in the north to Kaikoura to Westport in the south.