| Jurisdiction: | Diocese |
| Nouakchott | |
| Latin: | Dioecesis Nuakchottensis |
| Country: | Mauritania |
| Metropolitan: | Immediately exempt to the Holy See |
| Denomination: | Catholic Church |
| Sui Iuris Church: | Latin Church |
| Rite: | Roman Rite |
| Cathedral: | Cathedral of Saint Joseph, Nouakchott |
| Area Km2: | 1,030,700 |
| Population: | 2,600,000 |
| Population As Of: | 2004 |
| Catholics: | 4,500 |
| Bishop: | Victor Ndione |
| Emeritus Bishops: | Martin Albert Happe, M. Afr. |
The Diocese of Nouakchott is a Latin Church ecclesiastical territory or diocese of the Catholic Church situated in Nouakchott, Mauritania. It is the only Catholic ecclesiastical territory in Mauritania. The Cathedral of St. Joseph is located in Nouakchott.