The Roman Catholic Diocese of Darwin is a suffragan Latin Rite diocese of the Archdiocese of Adelaide based in Darwin, Northern Territory, Australia. As the largest diocese in Australia by the physical area covered, the Darwin diocese was initially administered by the Vicariate Apostolic of New Holland and Van Diemen's Land. In 1845 the Vicariate Apostolic of Essington was erected; becoming elevated as part of the Diocese of Victoria in 1847; as the Diocese of Victoria-Palmerston in 1888; and its name changed to the Diocese of Darwin in 1938.