| Jurisdiction: | Diocese |
| Rio Grande | |
| Latin: | Dioecesis Rivograndensis |
| Country: | Brazil |
| Province: | Pelotas |
| Rite: | Latin Rite |
| Cathedral: | Cathedral of St. Peter |
| Area Km2: | 12,270 |
| Population: | 300,000 |
| Population As Of: | 2014 |
| Catholics: | 211,000 |
| Catholics Percent: | 70.3 |
| Map: | File:Diocese de Rio Grande.svg |
The Diocese of Rio Grande (Portuguese: Diocese de Rio Grande, Latin: Dioecesis Rivograndensis) is a Roman Catholic diocese located in the city of Rio Grande in the ecclesiastical province of Pelotas in Brazil. The Diocese was established from the Diocese of Pelotas in 1971 and is located at the Cathedral of Saint Peter in Rio Grande.