The Roman Catholic Diocese of Mbulu (Latin: Dioecesis Mbuluensis) is a diocese located in the city of Mbulu in the ecclesiastical province of Arusha in Tanzania. The seat of the Bishop is the Cathedral Church of the Virgin Mary.

• April 14, 1943: Established as Apostolic Prefecture of Mbulu from the Apostolic Prefecture of Dodoma and the Apostolic Vicariate of Kilima-Njaro
• January 10, 1952: Promoted as Apostolic Vicariate of Mbulu
• March 25, 1953: Promoted as Diocese of Mbulu

• Prefect Apostolic of Mbulu (Roman rite)
  • Fr. Patrick Winters, S.A.C. (1944.01.28 – 1952.01.10 see below)
• Vicar Apostolic of Mbulu (Roman rite)
  • Patrick Winters, S.A.C. (see above 1952.01.10 – 1953.03.25 see below)
• Bishops of Mbulu (Roman rite)
  • Patrick Winters, S.A.C. (see above 1953.03.25 – 1971.07.03)
  • Nicodemus Atle Basili Hhando (1971.07.03 – 1997.03.07)
  • Jude Thaddaeus Ruwa'ichi, O.F.M. Cap. (1999.02.09 – 2005.01.15), appointed Bishop of Dodoma
  • Beatus Kinyaiya, O.F.M. Cap. (2006.04.22 - 2014.06.11), appointed Archbishop of Dodoma
  • Antony Gaspar Lagwen (since 2018.05.22)

• Roman Catholicism in Tanzania

• GCatholic.org
• Catholic Hierarchy

3°51′S 35°33′E / 3.85°S 35.55°E / -3.85; 35.55