O'Kelly's first school was the Sisters of Charity, in Mountjoy Street (1886–1890), then the Christian Brothers School in St Mary's Place (1890–1894). His senior school education was at O'Connell School, a Christian Brothers school in North Richmond Street (1894–1898). O'Kelly joined the National Library of Ireland in 1898 as a junior assistant to T. W. Lyster, remaining there until 1902, and becoming a subscriber to the Celtic Literary Society. The same year, he joined the Gaelic League, becoming a member of the governing body in 1910 and general secretary in 1915. He was appointed manager of An Claidheamh Soluis, which included amongst its editors the revolutionary leaders of Sinn Féin.Charles Townshend, "Easter 1916: The Irish Rebellion" (Penguin 2006), p. 412.
o'kelly's first school was the sisters of charity in mountjoy street (1886–1890) then the christian brothers school in st mary's place (1890–1894) his senior school education was at o'connell school a christian brothers school in north richmond street (1894–1898) o'kelly joined the national library of ireland in 1898 as a junior assistant to t w lyster remaining there until 1902 and becoming a subscriber to the celtic literary society the same year he joined the gaelic league becoming a member of the governing body in 1910 and general secretary in 1915 he was appointed manager of an claidheamh soluis which included amongst its editors the revolutionary leaders of sinn féincharles townshend "easter 1916 the irish rebellion" (penguin 2006) p 412