Láeg, or Lóeg, son of Riangabar, is the charioteer and constant companion of the hero Cú Chulainn in the Ulster Cycle of Irish mythology. His horses are Liath Macha and Dub Sainglend.

Cú Chulainn sends Láeg to the Otherworld with Lí Ban, sister to Fand, and he brings back bountiful descriptions of the Otherworld in the tale Serglige Con Culainn (The Sickbed of Cúchulainn). In the tale of Cú Chulainn's death he is killed by Lugaid mac Con Roí with a spear intended for Cú Chulainn.

• Serglige Con Culainn, ed. Myles Dillon (1953). Serglige Con Culainn. Mediaeval and Modern Irish Series 14. Dublin: DIAS.; tr. Jeffrey Gantz (1981). Early Irish Myths and Sagas. London: Penguin. pp. 155–78.
• Tochmarc Emire (Recension II), ed. A.G. van Hamel (1933). Compert Con Culainn and Other Stories. Mediaeval and Modern Irish Series 3. Dublin: DIAS.; tr. Kuno Meyer (1888). "The Wooing of Emer". Archaeological Review. 1: 68–75, 150–5, 231–5, 298–307.