Hugh Dubh O'Donnell (Irish: Aodh Dubh Ó Domhnaill; died 1618) was a member of the O'Donnell dynasty of Tyrconnell in modern-day County Donegal. He was the younger brother of Manus O'Donnell, the ruler of Tyrconnell between 1537 and 1555. When his brother died, Hugh Dubh unsuccessfully challenged for the Lordship which was held by his two nephews Calvagh O'Donnell and Sir Hugh O'Donnell. He was supported in his claim by Miler Magrath who suggested that his seniority in the family made him the rightful candidate.