The Roman Catholic Diocese of Viedma (Dioecesis Viedmensis) is encompassed in the Ecclesiastical Province of Bahía Blanca. As of 2006 the Bishop was Monsignor Esteban María Laxague, Salesian of Don Bosco appointed by Pope John Paul II on October 31, 2002. The Diocese was erected on April 20, 1934. It is suffragant to the Metropolitan Archdiocese of Bahía Blanca. His predecessor was HVRE Marcelo Angiolo Melani, Bishop from June 28, 1995 until 2002, when Laxague took over. Located in the Rio Negro Province, Argentina, the diocese has its see in the City of Viedma, by the shores of Río Negro River and close to the coast of the Atlantic Ocean. It encompasses a surface of about 89,000 square kilometers (34,000 sq mi).

• Nicolás Esandi, S.D.B. † (13 September 1934 – 29 August 1948) Died
• José Borgatti, S.D.B. † (28 August 1953 – 26 October 1973) Died
• Miguel Esteban Hesayne † (5 April 1975 – 28 June 1995) Resigned
• Marcelo Angiolo Melani, S.D.B. (28 June 1995 – 9 January 2002) Appointed, Bishop of Neuquén
• Esteban María Laxague, S.D.B. (31 October 2002 – Present)

• Marcelo Angiolo Melani, S.D.B. (1993-1995)

• Miguel Angel Alemán Eslava, S.D.B. (1968-1975), appointed Bishop of Río Gallegos
• Carmelo Juan Giaquinta (1980-1986), appointed Bishop of Posadas

• Roman Catholicism in Argentina
• Apostolic Vicariate of Northern Patagonia

• Diocese of Viedma ^{[self-published]}