| Jurisdiction: | Diocese |
| Foz do Iguaçu | |
| Latin: | Dioecesis Iguassuensis |
| Local: | Diocese de Foz do Iguaçu |
| Country: |  Brazil |
| Rite: | Latin Rite |
| Established: | 10 May 1926 (years ago) |
| Cathedral: | Cathedral of St John the Baptist in Foz do Iguaçu |
| Area Km2: | 6,822 |
| Population: | 521,000 |
| Population As Of: | 2013 |
| Catholics: | 413,000 |
| Catholics Percent: | 79.3 |
| Bishop: | Sérgio de Deus Borges |
| Website: | Website of the Diocese |
The Roman Catholic Diocese of Foz do Iguaçu (Latin: Dioecesis Iguassuensis) is a diocese located in the city of Foz do Iguaçu in the ecclesiastical province of Cascavel in Brazil.