Blathmac mac Con Brettan was an Irish poet and monk whose floruit was around 760.
Blathmac was the son of Cú Brettan mac Congussa (died 740), seemingly a king of the Airthir, one of the Airgíalla kingdoms, situated in modern-day County Armagh.
Cú Brettan and Donn Bó both appear as characters in the saga Cath Almaine and are portrayed as poets.
A manuscript containing his surviving poems, two meditations on the Virgin Mary, Tair cucum a Maire boid and A Maire, a grian ar clainde, once in the possession of Mícheál Ó Cléirigh, is in the National Library of Ireland, where it was re-discovered by Nessa Ní Shéaghdha in 1953.
[1] Art historian Peter Harbison says that st some point, Blathmac probably visited Rome as much of his poems reflect scenes depicted on mosaics in old Roman churches.