Conn O'Donnell was a member of the O'Donnell dynasty of Donegal.
The son of Calvagh O'Donnell, ruler of Tyrconnell, he was a candidate for the leadership of the O'Donnell chieftainship. He had four notable sons Niall Garve, Hugh Boy, Donal and Conn Oge O'Donnell.
References
Conn O'Donnell Wikipedia(Text) CC BY-SA