Clannad (Irish pronunciation: [ˈklˠan̪ˠəd̪ˠ]) were an Irish band formed in 1970 in Gweedore, County Donegal, by siblings Ciarán, Pól and Moya Ui Bhraonáin (in English, Brennan) and their twin uncles Noel and Pádraig Ó Dúgáin (Duggan). They have adopted various musical styles throughout their history. Beginning as an acoustic folk group mainly performing rearranged traditional Irish songs in Irish, they expanded their sound with original songs in English, vocal harmonies, electronic keyboards, and elements of rock, Celtic, new age, smooth jazz, and Gregorian chant.

Initially known as Clann as Dobhar ('Family from Dore'), they shortened their name to Clannad in 1973. By 1979 they had released three albums and toured Europe and the US. From 1980 to 1982 they operated as a six-piece with their sister and niece Eithne (Enya). In 1982 they gained international attention with their single "Theme from Harry's Game". They experimented with New Age and pop-influenced sounds in the 1980s and 1990s and their music came to be defined as almost purely Celtic, making them innovators of that genre. In 1997, after 15 albums, they took a break and pursued solo projects. The band regrouped in 2007 as a four piece with Moya, Ciarán, Noel and Pádraig and completed a world tour in 2008. In 2013, Pól rejoined and they released their first studio album in fifteen years. Pádraig Duggan died in 2016 and the group embarked on their farewell tour in 2020 as a quartet.

Clannad have won numerous awards throughout their career, including a Grammy Award, a BAFTA, an Ivor Novello Award, and a Billboard Music Award. They have recorded in six different languages and scored eight UK top 10 albums. They were often more popular abroad than in their native Ireland, and are considered to have brought Irish music and the Irish language to a wider audience.