Guðrøðr Óláfsson (died 10 November 1187) was a twelfth-century ruler of the kingdoms of Dublin and the Isles. Guðrøðr was a son of Óláfr Guðrøðarson, King of the Isles and Affraic, daughter of Fergus, Lord of Galloway. Throughout his career, Guðrøðr battled rival claimants to the throne, permanently losing about half of his realm to a rival dynasty in the process. Although dethroned for nearly a decade, Guðrøðr clawed his way back to regain control of a partitioned kingdom, and proceeded to project power into Ireland. Although originally opposed to the English invasion of Ireland, Guðrøðr adeptly recognised the English ascendancy in the Irish Sea region and aligned himself with the English. All later kings of the Crovan dynasty descended from Guðrøðr.