The Roman Catholic Diocese of Rarotonga (Latin: Dioecesis Rarotongana) in the Cook Islands is a suffragan diocese of the Roman Catholic Archdiocese of Suva in neighbouring Fiji.

It was erected as the Prefecture Apostolic of Cook and Manihiki in 1922, elevated to the Vicariate Apostolic of Cook Islands in 1948 and elevated as the Diocese of Rarotonga in 1966.

Primary Schools Saint Josephs School, Rarotonga Saint Mary's School, Mauke Island (now closed down) Secondary (High) School Nukutere College, Rarotonga Catholic Cathedral of Rarotonga (and the Cook Islands) Saint Joseph's Cathedral is the only Catholic Cathedral in the Cook Islands.

Three Catholic churches in Rarotonga also serve the local faithful: St Mary's in Arorangi Village, St Paul's in Titikaveka Village and Sacred Heart in Matavera village.

This article on a Roman Catholic diocese in Oceania is a stub.