The Roman Catholic Diocese of Musoma (Latin: Dioecesis Musomensis) is a diocese located in Musoma in the ecclesiastical province of Mwanza in Tanzania.

• November 4, 1946: Established as Apostolic Vicariate of Musoma-Maswa from the Apostolic Vicariate of Mwanza
• June 24, 1950: Demoted as Apostolic Prefecture of Musoma
• July 5, 1957: Promoted as Diocese of Musoma
• November 27, 2010: Territory lost to Roman Catholic Diocese of Bunda

• Vicar Apostolic of Musoma-Maswa (Roman rite)
  • Bishop Joseph Blomjous, M. Afr. (1946.04.11 – 1950.06.25), appointed Vicar Apostolic of Mwanza
• Prefect Apostolic of Musoma (Roman rite)
  • Fr. Giuseppe Gerardo Grondin, M.M. (1950 – 1957)
• Bishops of Musoma (Roman rite)
  • Bishop John James Rudin, M.M. (1957.07.05 – 1979.01.12)
  • Bishop Anthony Petro Mayalla (1979.01.12 – 1987.11.18), appointed Archbishop of Mwanza
  • Bishop Justin Tetmu Samba (1988.10.25 – 2006.08.23)
  • Bishop Michael George Mabuga Msonganzila (since 2007.11.10)

• Roman Catholicism in Tanzania

• GCatholic.org
• Catholic Hierarchy

1°30′S 33°48′E / 1.5°S 33.8°E / -1.5; 33.8