The Diocese of Laghouat (Latin: Dioecesis Laghuatensis) is a Latin Church ecclesiastical jurisdiction or diocese of the Catholic Church covering the sparsely populated Saharan inland of Algeria.

It is immediately exempt to the Holy See and not part of any ecclesiastical province, and depends on the missionary Roman Congregation for the Evangelization of Peoples.

The bishops cathedra is found in the Pro-Cathedral of Ghardaïa in the episcopal see of Ghardaïa. The former cathedral is the now-deconsecrated church of Saint Hilarion, in the city of Laghouat.

The diocese was established on 19 July 1901 as the Apostolic Prefecture of Ghardaïa (Latin: Ghardaiensis) on territory split off from the then Apostolic Vicariate of Sahara and Sudan (now the Archdiocese of Bamako in present Mali), also a pre-diocesan missionary jurisdiction. It was renamed on 10 January 1921 to the Apostolic Prefecture of Ghardaïa in the Sahara (Italian: Ghardaïa nel Sahara, Latin: Ghardaiensis in Sahara.)

On 28 April 1942, it lost western territory to establish the then Apostolic Prefecture of Niamey (now the Archdiocese of Niamey.)

The prefecture was promoted on 10 June 1948 to an apostolic vicariate, entitled to a titular bishop.

On 5 July 1954, it lost western territory again to establish the then Apostolic Prefecture of Spanish Sahara and Ifni (now named the Apostolic Prefecture of Western Sahara)

The vicariate was promoted on 14 September 1955 to the Diocese of Laghouat.

As of 2019^[update], it pastorally served 2,080 Catholics (0.0% of 4,902,760 total) on 2,107,708 km² in 10 parishes with 14 priests (3 diocesan, 11 religious) and 46 lay religious (20 brothers, 26 sisters) .

• List of Catholic dioceses in Algeria
• Roman Catholicism in Algeria

Wikisource has the text of the 1913 Catholic Encyclopedia article Ghardaia.

• GCatholic.org, with incumbent biography links - data for all sections
• Catholic Hierarchy
• Diocese of Laghouat Website (French)

32.4833°N 3.6667°E / 32.4833; 3.6667