The Diocese of Mzuzu is in Northern Malawi, bordered by Lilongwe Archdiocese to the south, Karonga Diocese to the north, Lake Malawi to the east, and Zambia to the west. Tumbuka is the main language for liturgical celebrations, with English used occasionally.
The diocese traces its origins to the Vicariate Apostolic of Nyassa. On 18th May 1947, the Prefecture Apostolic of Northern Nyassa was created, with Monsignor Marcel Saint-Denis, M. Afr., as its first Prefect. It was elevated to a diocese on 17th January 1961. Part of its territory became the Diocese of Karonga in 2010, and in 2011 Mzuzu shifted from the Blantyre to the Lilongwe Metropolitan.
Leadership has included Monsignor Marcel Saint-Denis (1947–1957), Monsignor Jean-Louis Jobidon (1958–1987), Bishop Joseph Mukasa Zuza (1995–2015), Bishop John Alphonsus Ryan (2016–2025), and currently Bishop Yohane Suzgo Nyirenda, installed in May 2025.