Cobthach mac Gabran was King of Ui Fiachrach Aidhne.
Cobthach's place among the early kings is uncertain.
His apparent predecessor, Goibnenn mac Conaill, is given as his uncle.
His apparent successor, Colmán mac Cobthaig, is given as his son.
The latter was the first king of Connacht from the Ui Fiachrach Aidhne.