| Jurisdiction: | Diocese |
| Cayenne | |
| Latin: | Dioecesis Caiennensis |
| Local: | Diocèse de Cayenne |
| Country: |  French Guiana, France |
| Metropolitan: | Archdiocese of Fort-de-France |
| Province: | Fort-de-France |
| Area Km2: | 1,780 |
| Population: | 260,000 |
| Population As Of: | 2013 |
| Catholics: | 188,000 |
| Catholics Percent: | 72.3 |
| Parishes: | 26 |
| Denomination: | Roman Catholic |
| Rite: | Latin Rite |
| Bishop Title: | Bishop |
| Bishop: | Alain Ransay |
| Metro Archbishop: | David Macaire |
| Emeritus Bishops: | Emmanuel Marie Philippe Louis Lafont |
| Website: | website of the Diocese |
The Roman Catholic Diocese of Cayenne (Latin: Dioecesis Caiennensis; French: Diocèse de Cayenne) (erected 1651, as the Prefecture Apostolic of French Guiana-Cayenne) is a suffragan diocese of the Archdiocese of Fort-de-France. It was elevated on to the Vicariate Apostolic of French Guiana-Cayenne on 10 January 1933 and to the Diocese of Cayenne on 29 February 1956. The seat of the bishop is in Cayenne Cathedral.