The Donohoe family are said to have two origins, one as part of the Clan Eoghanchta, and the other as part of the O’ Reilly clan, and both may be correct.
There is a story where there was a war in Kerry between two septs as to who would be king, and the peace was brokered by the Blennerhassets, who got the losing faction the right to settle in O’Reilly lands near where they had a branch in Fermanagh, and that’s how the Blennerhassets became established in Kerry and the Donohoes came to the Breiffne Marches.
In Irish its Ó Donnchadha ‘descendant of Donnchadh‘, a personal name (sometimes Anglicized as Duncan in Scotland), composed of the elements donn = ‘brown-haired man’ or ‘chieftain’ + cath = ‘battle’.
Donohoe Family Arms