The Kingsmill massacre was a mass shooting that took place on 5 January 1976 near the village of Whitecross in south County Armagh, Northern Ireland. Gunmen stopped a minibus carrying eleven Protestant workmen, lined them up alongside it and shot them. Only one victim survived, despite having been shot 18 times. A Catholic man on the minibus was allowed to go free. A group calling itself the South Armagh Republican Action Force claimed responsibility. It said the shooting was retaliation for a string of attacks on Catholic civilians in the area by Loyalists, particularly the killing of six Catholics the night before. The Kingsmill massacre was the climax of a string of tit-for-tat killings in the area during the mid-1970s, and was one of the deadliest mass shootings of the Troubles.

A 2011 report by the Historical Enquiries Team (HET) found that members of the Provisional IRA carried out the attack, despite the organisation being on ceasefire. The HET report said that the men were targeted because they were Protestants and that, although it was a response to the night before, it had been planned. The weapons used were linked to 110 other attacks.Following the massacre, the British government declared County Armagh to be a "Special Emergency Area" and hundreds of extra troops and police were deployed in the area. It also announced that the Special Air Service (SAS) was being moved into South Armagh. This was the first time that SAS presence in Northern Ireland was officially acknowledged.