The Diocese of Arua is located in the northwestern part (also known as the West Nile region) of Uganda. The Diocese is bordered to the north by Catholic Diocese of Torit and the Diocese of Yei (both in South Sudan); to the south by Nebbi Catholic Diocese (Uganda); to the east by Gulu Archdiocese (Uganda);and to the west by Diocese of Mahagi-Nioka (in Democratic Republic of Congo). The Diocese covers nine civil districts and one City: Adjumani, Arua,Arua-city, Koboko, Maracha, Moyo, Obongi, Terego, Yumbe and parts of Zombo. The diocesan headquarter and the Cathedral is located at Ediofe Mission, Arua City.

The territory of Arua Diocese was originally part of Gulu Diocese. Erected as a Diocese on June 23, 1958, its Patrons are the Sacred Heart of Jesus and Our Lady, Mediatrix of all Graces. The original territory included what is now Nebbi Diocese; The Catholic Diocese of Nebbi was erected on March 15, 1996.

The first Bishop of Arua Diocese was Rt. Rev. Angelo Tarantino of the Comboni Missionaries. He served from 1958 to 1984. The second Bishop of Arua Diocese was Rt. Rev. Frederick Drandua, first served as Apostolic Administrator and then was consecrated Bishop of Arua on August 15, 1986.He served until his retirement on August 19, 2009. The third and current Bishop of Arua Diocese, Rt. Rev. Sabino Ocan Odoki, was consecrated a Bishop on October 21, 2006 when he was appointed Auxiliary Bishop of Gulu Archdiocese. On August 19, 2009, he was appointed Apostolic Administrator of Arua Diocese. He was then appointed Bishop of Arua Diocese on October 20, 2010.