Aonghus Óg Mac Domhnaill (died 1314 × 1318/c. 1330), or Angus Og MacDonald, was a fourteenth-century Scottish magnate and chief of Clann Domhnaill. He was a younger son of Aonghus Mór mac Domhnaill, Lord of Islay. After the latter's apparent death, the chiefship of the kindred was assumed by Aonghus Óg's elder brother, Alasdair Óg Mac Domhnaill.