The Roman Catholic Diocese of MahagiâÂÂNioka (Latin: Romano-Catholicae Dioecesis Mahagi-Nioka, French: Diocèse catholique romain de Mahagi-Nioka) is a diocese located in the territories of MahagiâÂÂNioka, Ituri Province, in the ecclesiastical province of Kisangani in the Democratic Republic of the Congo.