Séamus Ennis was an Irish musician, singer and Irish music collector. He was most noted for his uilleann pipe playing and was partly responsible for the revival of the instrument during the twentieth century, having co-founded Na Píobairí Uilleann, a nonprofit organisation dedicated to the promotion of the uilleann pipes and its music. He is recognised for having preserved almost 2,000 Irish songs and dance-tunes as part of the work he did with the Irish Folklore Commission. Ennis is widely regarded as one of the greatest uilleann pipers of all time.

The uilleann pipes, sometimes called Irish bagpipes, are the characteristic national bagpipe of Ireland. Earlier known in English as "union pipes", their current name is a partial translation of the Irish language terms píobaí uilleann, from their method of inflation. There is no historical record of the name or use of the term uilleann pipes before the 20th century. It was an invention of Grattan Flood and the name stuck. People mistook the term 'union' to refer to the 1800 Act of Union; however, this is incorrect as Breandán Breathnach points out that a poem published in 1796 uses the term 'union'.