Clontarf is a coastal suburb on the northside of Dublin, in Ireland. It is most famous for the Battle of Clontarf in 1014, in which Brian Boru, High King of Ireland, defeated the Vikings of Dublin and their allies, the Irish of Leinster. This battle, which extended over a wide area, is seen as marking an end to the Irish-Viking Wars.
Clontarf lacks a single "village centre" but historically there were two population centres, one on the coast towards the city and the fishing village of Clontarf Sheds further north on the coast at what is now Vernon Avenue, in addition to the estate centred on Clontarf Castle. Clontarf has a range of commercial facilities in several locations, mainly centred on Vernon Avenue. It adjoins Fairview, Marino, Killester, Artane and Raheny, and is in the postal district Dublin 3.