The Latin Rite Roman Catholic Diocese of Dunedin (Dioecesis Dunedinensis) is a suffragan diocese of the Roman Catholic Archdiocese of Wellington. Its cathedral and see city are located in Dunedin, the second-largest city in the South Island of New Zealand. It was formed on 26 November 1869 from a portion of the territory in the Diocese of Wellington, before it was elevated to an archdiocese.