Séamus Ó Duilearga (born James Hamilton Delargy; 26 May 1899 – 25 June 1980) was an Irish folklorist, professor of folklore at University College Dublin and Director of the Irish Folklore Commission. Born in Cushendall, Co Antrim, he was one of two sons of James Delargy and Mary Josephine McQuillan. Following the death of James Delargy the family moved to Glenariff, Co Antrim and later to Co Wicklow. He resigned his UCD chair in 1969, retired from the Commission in 1971, and died in Dublin in 1980. Ó Duilearga was married to Maud McGuigan; they had one son and one daughter.