The Whiteboys were a secret Irish agrarian organisation in 18th-century Ireland which defended tenant-farmer land-rights for subsistence farming. Their name derives from the white smocks that members wore in their nighttime raids. Because they levelled fences at night, they were usually called "Levellers" by the authorities, and by themselves "Queen Sive Oultagh's children", "fairies", or followers of "Johanna Meskill" or "Sheila Meskill". They sought to address rack-rents, tithe-collection, excessive priests' dues, evictions, and other oppressive acts. As a result, they targeted landlords and tithe collectors. Over time, Whiteboyism became a general term for rural violence connected to secret societies. Because of this generalization, the historical record of the Whiteboys as a specific organisation is unclear. Three major outbreaks of Whiteboyism occurred: in 1761–1764, 1770–1776, and 1784–1786.

Father Nicholas Sheehy (1728–1766) was an 18th-century Irish Roman Catholic priest who was executed on the charge of being an accessory to murder. Father Sheehy was a prominent and vocal opponent of the Penal Laws, which subjected the whole Catholic Church in Ireland to religious persecution, and as a vocal activist for Catholic Emancipation. His conviction was widely regarded as a judicial murder and was cited long afterwards as Irish jargon for a miscarriage of justice. Fr. Nicholas Sheehy is currently regarded as one of the Irish Catholic Martyrs.