Sheehy, Nicholas (c.1728–1766), priest, was born near Fethard, Co. Tipperary, son of Francis Sheehy, and grandson of John Sheehy (d. 1740), who had married into the Power family of Bawnfune, parish of Kilronan, Co. Waterford, and who thereby became head tenant to over 600 acres on the estate of Lord Midleton (qv). Nicholas was educated at Louvain and ordained in Rome in 1752. After his return to Ireland he became curate of Newcastle, Co. Tipperary, close to his Bawnfune home, and later parish priest of the united parishes of Shanrahan, Ballysheehan, and Templetenny, which later became the parishes of Clogheen and Burncourt. He first came to public attention in 1758 when he was included in a list of priests who were required by the catholic bishop of Cloyne, John O'Brien (qv), to publicise in their respective parishes an edict of excommunication which he had placed on the town of Michelstown, Co. Cork. The landlord of the area, Lord Kingston, fearing an undermining of his authority, offered a reward of £5 for the apprehension of each priest, including Sheehy.
Clogheen, where Sheehy ministered, became the centre of Whiteboy activity in the early 1760s. He sympathised with Whiteboy grievances, though whether this meant active involvement is uncertain. Certainly, the enclosure of commons and the high rent for potato ground caused population movement from his parishes, his income (said to have been a considerable £200 a year) was diminished as a result, and this may have predisposed him to acquiesce in Whiteboy aims. Sheehy publicly condemned, and encouraged resistance to, novel claims being made in Ballyporeen by a tithe farmer in 1762, and he opposed the collection of church rates and tithes in Newcastle parish.
The inability of the Tipperary grand jury to obtain convictions for Whiteboy acts was a source of embarrassment to them. Madden suggests that Sheehy collected funds for the defence of those accused of such outrages, and that their subsequent acquittal was attributed to him. Inability to obtain convictions for Whiteboy offences, coupled with multiple expressions of catholic assertiveness, in the eyes of the county gentry presaged an alliance with the French enemy with the intent of overthrowing the established order in church and state. Sheehy was viewed as a leader intent on raising rebellion and (in league with the French) reversing the land settlement and undoing the penal laws. The effect was to unleash a sectarian witch hunt, the prime victim of which was Sheehy.
Acting under expanded powers given to them, local magistrates sought Sheehy and other priests, who were eventually apprehended and charged at the summer assize of 1762 with being unregistered priests. In May 1763 Sheehy was indicted for forcing people not to inform against the Whiteboys, a charge that appears to have been dropped. In March 1764 he was indicted for unlawful assembly for the intent of rebellion, and further indictments followed, but these seemingly were without effect.
The government tried to get Sheehy to surrender to an intermediary, but before it could be put into effect he fled to relatives in Limerick. Continued frustration in 1763–4 at the lack of Whiteboy convictions led the magistrates in February 1765 to offer a reward of £300 for Sheehy's capture, an unusually high amount as rewards went. Sheehy surrendered voluntarily and though he was bailed in June 1765 (in the amount of £4,000), eleven months elapsed (because of questionable delays in assembling the prosecution case) before he stood trial in February 1766 charged with incitement to riot and rebellion, but he was acquitted. This outcome was not unforeseen by his prosecutors, for he was immediately indicted on a murder charge that related to the disappearance in late 1764 of John Bridge, a key informant against the priest. At his trial in Clonmel, despite the defence case that the prosecution witnesses were of dubious character, that it had an alibi for the priest's location on the night of Bridge's murder, and that there was no firm evidence that Bridge had been murdered since the body was never found, Sheehy was convicted of murder on 12 March and executed on 15 March 1766. He protested his innocence to the end and suggested that the real murderers of Bridge had been revealed to him in the confessional, information which by virtue of his clerical office he could not use in his own defence.
The partial nature of justice exhibited by Sheehy's conviction is further confirmed by the fact that he was found guilty on the evidence of three witnesses whose same evidence had been rejected in his Dublin trial. Also two of three others who were executed in May, on the same murder charge as Sheehy, declared that they had been approached by some magistrates to turn approver and swear that ‘the priest Sheehy died with a lie in his mouth.’ Further, one of those who gave testimony in the trial of Roger Sheehy (1767) prevaricated in his evidence from what he swore against Fr Sheehy a year earlier. The partial nature of justice is indicated by the coining of the term ‘Sheehy's jury’ as applied thereafter to any jury which acted in an arbitrary fashion. Popular reaction to Sheehy's execution is indicated by the stoning to death of his executioner by a crowd at Phillipstown in 1770. In due course Sheehy came to be regarded as a martyr of catholic Ireland, the subject of poems and laments, and his grave in Shanrahan became the object of pilgrimage.