Note: Joseph James O'Neill was born in Tuam, County Galway, on December 18, 1878, but spent much of his boyhood on the Aran Islands where his father, a member of the Royal Irish Constabulary, had been stationed. He returned to the mainland in 1893 to attend St. Jarlath's College in Tuam, and later, from 1898 to 1901, Queen's College, Galway, from which he received his B.A. and M.A. in modern literature.
He joined the civil service in 1908 as second class inspector of primary schools. After his marriage to Mary Devenport, on June 29, 1908, he rose rose quickly in the Department of Secondary Education and was appointed its permanent secretary in 1923, a post he held until his retirement in 1944.
Walking in the Wicklow Hills in the early spring of 1952, he suffered a cerebral hemorrhage and was brought to St. John of God's Nursing Home in Stillorgan, Dublin, where he died on May 6.
(source: excerpt from the entry by M. Kelly Lynch in the Macmillan Dictionary of Irish Literature edited by Robert Hogan)
Wikipedia gives his birth year as 1886, in error.