| Jurisdiction: | Diocese |
| Três Lagoas | |
| Latin: | Dioecesis Trilacunensis |
| Local: | Diocese de Três Lagoas |
| Country: | Brazil |
| Rite: | Latin Rite |
| Established: | 3 January 1978 (year ago) |
| Cathedral: | Cathedral of St Anthony in Três Lagoas |
| Area Km2: | 49,000 |
| Population: | 243,000 |
| Population As Of: | 2010 |
| Catholics: | 183,000 |
| Catholics Percent: | 75.3 |
| Bishop: | Luiz Gonçalves Knupp |
The Roman Catholic Diocese of Três Lagoas (la|Dioecesis Trilacunensis) is a diocese located in the city of Três Lagoas in the ecclesiastical province of Campo Grande in Brazil.