Brandubh is the name of three Irish bishops.
(1) Commemorated June 3. The Mart. Donegal. says, "This may be Brandubh, the bishop, son of Maenach, race of Mac Con." Colgan (Acta Sanctorum, 596, n.). calls him bishop, and places him among the seven brothers (saints) of St. Fagnenus (or Fachtnla), bishop of Ros-Alethir, now Ros-Carbery, County Cork; while in Tr. Thaum. 383, n., he gives his complete genealogy (A.D. 196-225).
(2) Commemorated February 6. Of Lochmuinremhair, i.e., Loch Ramor, in Cavan. The Mart. Donegal. says, "There is a Branduh, bishop, of the race of Eochaidh, son of Muireadh, race of Heremon. Among the saints of the family of Maccarthenus, Colgan (Acta Sanctorum, page 741, col. 2) cites "Brandubius Episc.; videtur esse qui colitur Lochmunreamhar in Ultonia, February 6."
(3) Bishop, June 13. In Colgan's Life of St. Fintan (Acta Sanctorum, 352) there is mentioned a bishop named Brandubh, "vir sapiens, mitis, humilis," from the district of Kinsealach, who came to abbot Fintan of Clonenagh, to his monastery of Achadh-Finglaiss, to be a monk and end his days there.