Iarla Ó Lionáird (also commonly spelled Iarla Ó Lionaird and Iarla O'Lionaird) is an Irish singer well known for his contributions in the band Afro Celt Sound System. He is one of the most prominent artists of the Irish Sean nós singing tradition, and has released three solo albums through EMI/Real World Records, the third being Invisible Fields, released in August 2005.