Father James Coigly (aka James O'Coigley and James/Jeremiah Quigley) (1761 – 7 June 1798) was a Roman Catholic priest in Ireland active in the republican movement against the British Crown and the kingdom's Protestant Ascendancy. He served the Society of United Irishmen as a mediator in the sectarian Armagh Disturbances and as an envoy both to the government of the French Republic and to radical circles in England with whom he sought to coordinate an insurrection. In June 1798 he was executed in England for treason having been detained as he was about to embark on a return mission to Paris.

The second son of Louisa (née Donnelly) and James Coigly, Coigly was born in 1761 into a small farming/weaving family in Kilmore, County Armagh in the Kingdom of Ireland. He was proud of his ancestry, having had great grandfathers who had fought and died in the Jacobite cause at Derry and the Boyne.

During his formative years the Penal Laws, which had systematically excluded Ireland's Roman Catholic majority from land ownership, the professions and public office, were by stages relaxed. Catholic families of at least middling income could aspire to educate their sons. Coigly was sent to Dundalk Grammar School for classical studies. Despite this being a Protestant school he acquired a religious vocation.

After Dundalk Coigly entered the priesthood in the archdiocese of Armagh. In January 1785 he was ordained by the Coadjutor Bishop of Armagh Richard O'Reilly. In the absence of a seminary in Ireland, he was sent for further studies to the Collège des Lombards (the Irish College) in Paris where Irish students, bound for careers not only in the Church but also in law, medicine, or in service with the Irish Brigade in the French army were taught.

Coigly has been described as "no friend of the [French] revolution". He stayed in Paris until 12 October 1789, by which time Louis XVI had been brought back from Versailles by the women of Paris and clerical members had been hounded from National Assembly. By his own account Coigly, himself, narrowly escaped "lanternisation" (being hung from a street lantern) by a mob who took his clerical garb as a token of royalist sympathies. But relayed while on trial for his life in 1798, his story of escaping revolutionary justice may be no more reliable that his general protestations of political innocence. According to William MacNeven, only the year before, Coigly had been exciting "almost extravagant" joy among "the Coventanters" of Antrim and Down by proclaiming that "this Romish priest is so sincere a lover of liberty, as to have been actually fighting at the capture of the Bastille" (something which, if true, would have placed Coigly in the company of his fellow collegiate James Bartholomew Blackwell).

At the College in Paris, Coigly had already demonstrated what the historian of the diocese of Down and Conor recorded as the "systematic insubordination" that was the "forerunner of his sad and subsequent career, which terminated on the scaffold". Coigly took the unprecedented step of initiating legal proceedings against the college to secure a scholarship, and then followed this up with an appeal to restore to students the right to elect their superiors.

In Paris, Coigly would have been familiar with the work of the Irish theologian Luke Joseph Hooke. "A representative of the Catholicism of the Enlightenment", Hooke argued that the laws of civil society should be so designed that men can conform to the natural rights ordained by God of their own free will. The just state and the true religion were one and the same.

In Ireland the French Revolution had revived the Volunteer movement in Presbyterian Belfast and its hinterlands and emboldened the Catholic Committee in Dublin. As the government made clear the limits for potential reform, more radical elements in the two centres formed themselves as the United Irishmen. Drawing on the growing discontents of tenant farmers, market-town traders, journeymen and weavers, United Irish "societies" multiplied rapidly across Ulster and the Irish midlands.