Born in Galway, he moved to London as a teenager, where he became a DJ at local discos and clubs. When he returned to Ireland, he got a job in Radio Éireann presenting 'Popseó na Máirte' (1969), the first Irish-language pop show. He later moved into television, presenting folk-music programme 'Imeall'and and 'SBB ina Shuí' (1976-82).
Breathnach currently presents 'Spórt an tSathairn' on RTÉ Raidió na Gaeltachta, featuring sporting reports, interviews and previews. He is renowned for his passionate, emotional and thrilling commentary of sporting events.