On 30th January 1999, the Holy See elevated Mbarara to an Archdiocese and Metropolitan See of the Western Uganda Ecclesiastical Province, with Paul Bakyenga as its first Archbishop. This significant elevation marked a new chapter in the region's ecclesiastical history, highlighting the growth and importance of the Catholic community in Western Uganda.
On 25 March 1953, Rwenzori Vicariate assumed status of a diocese. In 1956 Bishop F.X. Lacoursiere retired after 21 years as Diocesan Bishop. The second Bishop of Mbarara Diocese was Jean Marie Ogez, ordained a bishop on 26 August 1957. Due to poor health, Bishop Ogez retired in October 1968. The third ordinary and first indigenous African Bishop was John Baptist Kakubi.
He was appointed on 5th July 1969 and ordained Bishop on 1st August 1969. He retired on 23rd November 1991. Archbishop Paul K. Bakyenga was the fourth bishop of Mbarara, he was appointed Bishop Coadjutor of Mbarara on 1St April 1989. He was ordained a Bishop on 24 June 1989, and became Bishop Ordinary of Mbarara on 23 November 1991. He was installed Archbishop of Mbarara on 11th July 1999.
The Rwenzori Vicariate was carved out of the Vicariate of Uganda on 28th March 1934. This new ecclesiastical territory initially covered the political districts of Western Uganda, namely Nkore, Kigezi, Toro, and Bunyoro. Over time, the vicariate expanded and evolved into what is now known as the Archdiocese of Mbarara. The present archdiocese encompasses a wide range of districts, including Mbarara, Ibanda, Kiruhura, Kazo, Isingiro, Bushenyi, Ntungamo, Mitooma, Buhweju, Sheema, Rubirizi, Rwampara, and Mbarara City.