Ó Cadhlaigh, Cormac (1884–1960), Celticist, was born 26 April 1884, in Kinsale, Co. Cork, one of seven children of shoemaker Jeremiah Ó Cadhlaigh and his wife, Marianne McCarthy. His mother had trained as a teacher but never entered the profession and instead managed Clarke's tobacco shop in Kinsale. Ó Cadhlaigh's maternal aunt, Myra McCarthy, became well known for allowing Michael Collins (qv) to use her home as a safe house while on the run. Nothing is known of Ó Cadhlaigh's primary education. He attended Coláiste Cholmáin in Fermoy between 1895 and 1897 and afterwards Coláiste Cheathramhan in Ceathrú an Tobair between 1897 and 1901. He first began to learn the Irish language with the assistance of Ó Gramhnaigh's Irish grammar book when he was seventeen. A feis held in Baile an Mhairtéiligh in July 1901 marked a turning point in his life and served to increase his interest in Irish although he could still understand only very little of it at that stage. It was not long, however, before he had become competent in the language, having spent time on the Blasket islands. The period he spent there preceded the arrival of scholars such as Robin Flower (qv) and Carl Marstrander (qv).
He obtained a post with Conradh na Gaeilge in 1905 in Graiguenamanagh, Co. Kilkenny. The same year he qualified as an Irish teacher from Coláiste na Mumhan, Ballingeary, Co. Cork. He began teaching in St Joseph's College, Ballinasloe, Co. Galway in September 1905 where he remained two years. By 1907 he was employed as a timire for Conradh na Gaeilge in Co. Clare. Together with Thomas MacDonagh (qv) and Pádraig Ó Cinnéide he founded the Association of Secondary School Teachers in Ireland (ASTI). The same year he began teaching Irish and French in Coláiste Cholmáin in Fermoy and spent three years teaching Spanish and five years teaching commerce. He published a book on accountancy in 1925. Between 1909 and 1917 he taught special Irish classes in the Loreto convent and evening commerce classes in the vocational schools in Fermoy and Mitchelstown, Co. Cork from 1918 until 1921. During the summers of 1914 to 1917 he taught Irish courses in Caherdaniel, Co. Kerry. He also taught in the Tramore branch of Coláiste na Rinne in 1921.
His study of the Irish language began in earnest during his time in Coláiste Cholmáin as the college owned a substantial collection of Irish language manuscripts. He published a version of Párliament na mban in Lóchrann from the college's collection in 1909. Two years later his ‘Eachtra Chondla Mic Chuinn chéadchathaigh’ from Leabhar na hUidhre, also appeared in Lóchrann. Between 1912 and 1913 he published ‘Ceisneamh inghine ghoil Átha Lóigh’ in the same publication. At this time he began an in-depth study of the work of Fr Peadar Ó Laoghaire (qv) who lived four miles away from him and whom Ó Cadhlaigh regularly visited. Already by this stage Ó Cadhlaigh had begun to study privately for a Bachelor of Arts (BA) which he obtained in 1912 and a Master of Arts (MA) in 1913, excelling in both degrees.
He continued his study of the Irish language, publishing Ceart na Gaedhilge (1922) and Gnás na Gaedhilge (1940). Between 1921 and 1923 he published a number of essays as well as an edition of De bello Gallico leabhar a 2. He published Slighe an eolais (1923) and in November that year began work as an assistant in the Irish department and library in University College Cork (UCC). His publications at this time included a number of translations: Eagna an Ghaedhil (1926), an explanation of archaic words; Cuntasaíocht (1925); Stáit an lucht saothair (1926), a translation of Leo XIII's Rerum Novarum; Cormac Mac Airt (1927); Aindeise Shiobhán (1928), a translation of Eugene de Segur's Les malheurs de Sophie; Columba (1929), a translation of a story by Prosper Mérimée; Rí na gcnoc (1931), a translation of Edmond About's Le Roi des montagnes; and also ‘Geineallaighe Fearmanach’ was published in Analecta Hibernica, no. 3 (Sept. 1931). He was editor of An Lóchrann from February 1930 to December 1931 and was promoted to lecturer in UCC in April 1931. The following year, July 1932, he was appointed to the chair of modern Irish in University College Dublin (UCD), succeeding Douglas Hyde (qv) in the post. During this period he published two significant works, An fhiannaidheacht and An rúraíocht. He also published Guaire an oinigh and Diarmaid Mac Cearbhaill. In 1943 he applied for the presidency of UCC but was unsuccessful, losing to Alfred O'Rahilly (qv). He retired from UCD in 1954.
In 1913 Ó Cadhlaigh married Esther Nic Cormaic from Killorglin, Co. Kerry, and they had three daughters and one son. Her parents owned the Railway Hotel in Killorglin, and she died in 1947. Towards the end of his life Ó Cadhlaigh began to write his autobiography but this remained unfinished. He died 1 December 1960.
More information on this entry is available at the National Database of Irish-language biographies (Ainm.ie).