The Roman Catholic Diocese of Bougainville is a suffragan diocese of the Roman Catholic Archdiocese of Rabaul. It was erected as the Prefecture Apostolic of German Solomon Islands in 1898 and elevated to a Vicariate Apostolic in 1930. It was further elevated in 1966 to the Diocese of Bougainville.
The diocesan cathedral is the Our Lady of the Assumption Cathedral, Buka. It was previously the Church of St. Michael the Archangel at the former Tubiana mission.[1][2]