Arthur Edward Clery (25 October 1879 – 20 November 1932) was an Irish republican politician and university professor.
Clery was born at 46 Lower Leeson Street, Dublin, to Arthur Clery (who also used the names Arthur Patrick O'Clery and Arthur Ua Cléirigh), a barrister, and Catherine Moylan. His father, who practised in India, published books on early Irish history and was politically an associate of Isaac Butt.
Clery was brought up to a considerable extent by a relative, Charles Dawson. A cousin, William Dawson (who used the pen-name "Avis"), became his closest friend and associate. Clery was educated at the Catholic University School on Leeson Street (where he acquired the confirmation name "Chanel" in honour of the Marist martyr Peter Chanel, which he often used as a pseudonym), at Clongowes Wood College, and University College in Stephen's Green. He was a university contemporary of James Joyce.
Clery's principal themes included the difficulties of Roman Catholic graduates seeking professional employment, dramatic criticism (he hailed Lady Gregory's play Kincora as the Abbey Theatre's first masterpiece but was repulsed by the works of Synge), Catholic-Protestant rivalry, tension within the Dublin professional class, and the vagaries of the Gaelic revival movement (including Clery's own attempts to learn Irish in Ballingeary, and such questions as whether a true Gael should play tennis).
Clery advocated partition on the basis of a two-nation theory, first advanced in 1904–05 (possibly in response to William O'Brien's advocacy of securing Home Rule through compromise with moderate Unionists). Several of his articles on the subject were reprinted in his 1907 essay collection, The Idea of a Nation.
Clery derived this unusual view for a nationalist from several motives, including a belief that arguments for Irish nationalists' right to self-determination could be used to justify Ulster Unionists' right to secede from Ireland, fear that it might be impossible to obtain Home Rule unless Ulster were excluded, and distaste for both Ulster Protestants and Ulster Catholics, whom he saw as deplorably anglicised. He remained a partitionist for the rest of his life. Clery was not particularly successful as a barrister, but on the establishment of University College Dublin (UCD) in 1909 he was appointed to the part-time post of Professor of the Law of Property.