| Jurisdiction: | Diocese |
| Blumenau | |
| Latin: | Dioecesis Florumpratensis |
| Local: | Diocese de Blumenau |
| Country: |  Brazil |
| Rite: | Latin Rite |
| Established: | 19 April 2000 (years ago) |
| Cathedral: | Cathedral of St Paul in Blumenau |
| Area Km2: | 3,388 |
| Population: | 609,000 |
| Population As Of: | 2004 |
| Catholics: | 430,000 |
| Catholics Percent: | 70.6 |
| Parishes: | 38 |
| Bishop: | Rafael Biernaski |
| Metro Archbishop: | Wilson Tadeu Jönck, SCI |
| Emeritus Bishops: | Angélico Sândalo Bernardino Bishop Emeritus |
| Map: | File:Diocese de Blumenau.svg |
| Website: | Website of the Diocese |
The Roman Catholic Diocese of Blumenau (Latin: Dioecesis Florumpratensis) is a diocese located in the city of Blumenau in the ecclesiastical province of Florianópolis in Brazil.