Oisín Mac Diarmada is an Irish fiddler. He began playing the fiddle at an early age and was winning competitions by age eight. In 1988, he secured the Fiddle Solo and Duet titles as the All-Ireland Junior Champion at Fleadh Cheoil. His family moved to County Sligo in 1989, where he attended the music school in Ballymote and later studied classical piano. Mac Diarmada won the All-Ireland Fiddle Championship at Fleadh Cheoil in 1999 and graduated from Trinity College Dublin and the Royal Irish Academy of Music in 2000. In 2001, he co-founded the traditional music group Téada with Seán McElwain and Tristan Rosenstock. He has released several albums, including Traditional Music on Fiddle, Banjo & Harp (2000) with Brian Fitzgerald and Michael Rooney, Ar An BhFidil (2004), and The Green Branch (An Géagán Glas) (2015).