"O'Donnell Abú" (Irish: Ó Domhnaill Abú) is a traditional Irish song. Its lyrics were written by a Fenian Michael Joseph McCann in 1843. It refers to the Gaelic lord Red Hugh O'Donnell who ruled Tyrconnell in the late sixteenth century, first with the approval of the Crown authorities in Dublin and later in rebellion against them during Tyrone's Rebellion. The title refers to the Gaelic war cry of "Abú," "To victory," which followed a commander's name.