| Jurisdiction: | Diocese |
| Daltonganj | |
| Latin: | Dioecesis Daltonganiensis |
| Rite: | Latin Rite |
| Cathedral: | Shanti ki Maharani church, Medininagar |
| Established: | 5 June 1971 |
| Area Km2: | 2,750 |
| Population: | 3,358,000 |
| Population As Of: | 2022 |
| Catholics: | 69,200 |
| Catholics Percent: | 2.1 |
| Bishop: | Theodore Mascarenhas |
| Metro Archbishop: | Vincent Aind |
| Parishes: | 23 |
| Patron: | Shanti Ki Maharani |
| Priests: | 43 |
| Emeritus Bishops: | Gabriel Kujur |
The Roman Catholic Diocese of Daltonganj (Latin: Daltonganien(sis)) is a diocese located in the city of Daltonganj in the ecclesiastical province of Ranchi in India.