Born in Carna, Conamara, County Galway the son of a fisherman, his siblings were Joe, Matt, Páraic,Bairbre, Bríd, Máiréad, Nóra, Eilís and Mary.
A schoolfriend of Seosamh Ó hÉanaí, 'ac Dhonncha won a scholarship to Coláiste Éinde and qualified as a primary teacher in 1940.
He was the first traditional singer to record with Gael Linn; won a gold medal at the 1953 Oireachtas; and was awarded the Gradam Shean-Nós Cois Life in 1995.
In 1971, Claddagh Records released An Aill Báin (The White Rock): Songs in Irish and English from Connemara.
In 1994, Cló Iar-Chonnachta released a CD of his songs in Irish and English, entitled Seán 'ac Dhonncha: An Spailpín Fánach."