| Jurisdiction: | Diocese |
| Roskilde | |
| Latin: | Dioecesis Roskildensis |
| Local: | Roskilde Stift |
| Country: | Denmark |
| Province: | Lund |
| Metropolitan: | Archdiocese of Lund |
| Denomination: | Roman Catholic |
| Sui Iuris Church: | Latin Church |
| Established: | 991 |
| Dissolved: | 1536 |
| Cathedral: | Roskilde Cathedral |
The former Diocese of Roskilde was a diocese within the Roman-Catholic Church which was established in Denmark some time before 1022. The diocese was dissolved with the Reformation of Denmark and replaced by the Protestant Diocese of Zealand in 1537.[1]
Today, the region once within the Diocese of Roskilde's jurisdiction is part of the Roman Catholic Diocese of Copenhagen. Within the Church of Denmark, the region formerly within the ancient Diocese of Roskilde is today divided between the Diocese of Copenhagen, the "new" Diocese of Roskilde, and the Diocese of Helsingør.
The episcopal see of the Bishop was Roskilde Cathedral but from 1167, when Bishop Absalon completed a new bishop's palace known as Absalon's Castle on the small island of Slotsholmen, he resided at the small town of Havn, which later became the present Danish capital Copenhagen.
The diocese originally included both the island of Zealand and Scania (southern Sweden, then part of Denmark), but Scania was disjoined in 1060 and initially divided into the short-lived Diocese of Dalby and the Diocese of Lund, which absorbed the first and became the Metropolitan of (southern) Scandinavia.