| Jurisdiction: | Diocese |
| Bydgoszcz | |
| Latin: | Dioecesis Bydgostiensis |
| Local: | Diecezja Bydgoska |
| Country: |  Poland |
| Metropolitan: | Gniezno |
| Rite: | Latin Rite |
| Cathedral: | Cathedral of St. Martin and St. Nicholas in Bydgoszcz |
| Area Km2: | 4,000 |
| Population: | 622,036 |
| Population As Of: | 2020 |
| Catholics: | 583,088 |
| Catholics Percent: | 93.7 |
| Metro Archbishop: | Wojciech Polak |
| Bishop: | Krzysztof Włodarczyk |
| Emeritus Bishops: | Jan Tyrawa |
| Map: | Roman Catholic Diocese of Bydgoszcz location map.svg |
| Website: | Website of the Diocese |
| Denomination: | Catholic Church |
The Diocese of Bydgoszcz (la|Dioecesis Bydgostiensis ) is a Latin Church ecclesiastical territory or diocese of the Catholic Church located in the city of Bydgoszcz in the ecclesiastical province of Gniezno in Poland.