Dunne attended St Michael's College, Dublin and entered the Leinster sub-academy immediately upon leaving school in 2017 before being promoted to the full academy in the Summer of 2018. He was selected for the Ireland U20s in the 2018 Six Nations Under 20s Championship and at the 2018 World Rugby Under 20 Championship. Captained the Seapoint U10s B team in 2008.