The Pan Celtic Festival is a Celtic-language music festival held annually in the week following Easter, in Ireland, since its inauguration in 1971. The first Pan Celtic Festival took place in Killarney, County Kerry, Ireland. Its aim is to promote the modern Celtic languages and cultures and artists from six Celtic nations: Brittany, Cornwall, Ireland, Isle of Man, Scotland and Wales.

The Celtic nations or Celtic countries are a cultural area and collection of geographical regions in Northwestern Europe where the Celtic languages and cultural traits have survived. The term nation is used in its original sense to mean a people who share a common identity and culture and are identified with a traditional territory.