After studying at St Malachy's Diocesan College in Belfast and Maynooth College he entered the Roman Catholic priesthood and in 1906 he was appointed parish priest of the Sacred Heart parish, Oldpark Road, Belfast.
The Order of the Knights of St Columbanus was formally founded in 1922. The organisation arose, however, in the period before the Great War, when working people and others were organising themselves as never before into trade unions, friendly societies, temperance societies, Hibernian, Orange, Masonic and other groups based upon the brotherhood ideal. Father James K O'Neill, a parish priest in Belfast's Oldpark district, who was much concerned with the then recently defined Roman Catholic 'social principles' tried to draw Catholic men into a society 'to cherish fraternal charity and to develop practical Catholicity among its members, to promote and foster the cause of the Catholic faith and Catholic education'. By early 1916 there were four 'Councils of Knights' in Belfast from which they assembled a Board of Governors. Soon more Councils of Knights were formed in Armagh, Cork, Derry, Dublin, Lurgan, Newry and Portadown.
Meanwhile, there was already in esistence a body known as the Columban Knights whose aims seemed to have been very much the same as the Knights of St Columbanus. At the insistence of Archbishop Byrne, who had bneen one of the first priest-members of the Columban Knights, these two Orders were amalgamated and effectively the present Order of the Knights of St Columbanus came into existence.In the early years, the Knights of St Columbanus had secret signs and rituals in the same manner as other brotherhoods. Its rituals were based on those of an American Catholic organisation, the Knights of St Columbus. Nowadays, as has happened in many other brotherhoods, the original secretive rituals have been modified to a non-secret and simpler form.