Donnubán ('donuva:n), Donndubán ('donðuva:n), or Donnabán mac Cathail, anglicised Donovan, son of Cahall (died 980), was a tenth-century ruler of the Irish regional kingdom of Uí Fidgenti, and possibly also of the smaller overkingdom of Uí Chairbre Áebda within that. In contemporary sources he is only named king of the former, but his sons and later descendants appear as dynasts of the latter. In addition, at his death in 980 Donovan is styled King of Ressad, a unique title in the surviving Irish annals, and the identity of which place is uncertain. He is the progenitor of the medieval and modern O'Donovan family.