The Bologna massacre (Italian: strage di Bologna) was a terrorist bombing of the Bologna Centrale railway station in Bologna, Italy, on the morning of 2 August 1980, which killed 85 people and wounded over 200. Several members of the neo-fascist terrorist organization Nuclei Armati Rivoluzionari (NAR, Armed Revolutionary Nuclei) were sentenced for the bombing, although the group denied involvement. Investigations in the 2020s, and following prosecutions from the Bologna Corte d'Assise, declared Licio Gelli, along with other members of the masonic lodge and secret society Propaganda Due, as the mastermind behind the massacre.

At 10:25 CEST, a time bomb hidden in an unattended suitcase detonated in an air-conditioned waiting room at the Bologna station, which was full of people seeking relief from the August heat. The explosion collapsed the roof of the waiting room, destroyed most of the main building, and hit the Ancona–Chiasso train, which was waiting at the first platform.

The station was full of tourists that Saturday, and the city was unprepared for a major disaster. Many passers-by and travellers provided first aid to victims and helped rescue people who were buried under the rubble.^{[citation needed]}

Due to the large number of casualties and an insufficient number of emergency vehicles available to transport the injured to hospitals, firefighters used buses, private cars, and taxis. Some doctors and hospital staff returned early from vacation to care for the victims, and hospital departments which were closed for the summer holidays were reopened to accommodate the casualties.^{[citation needed]}

After the attack, large demonstrations were held in Piazza Maggiore (Bologna's central square). Harsh criticism was directed at government representatives who attended the 6 August funerals of the victims in the Basilica San Petronio. The only applause was reserved for President Sandro Pertini, who arrived by helicopter in Bologna at 5:30 pm the day of the massacre and tearfully said: "I have no words; we are facing the most criminal enterprise that has ever taken place in Italy."

The #37 bus (used to transport victims) and the clock (stopped at 10:25) were symbols of the massacre. The attack was the worst atrocity in Italy since World War II. According to a 1982 study covering the effects of the bombing, 291 were injured, of whom 73 died at the scene, and an additional 11 people died in hospitals.

The government, led by Christian Democratic Prime Minister Francesco Cossiga, first assumed that the incident was due to an accidental explosion of an old boiler in the station's basement. Evidence, however, soon pointed to terrorism. L'Unità, the Italian Communist Party (PCI) newspaper, attributed responsibility for the attack to neo-fascists on 3 August. Later, in a special session of the Senate, Cossiga also supported the theory that neo-fascists were behind the attack: "Unlike leftist terrorism, which strikes at the heart of the state through its representatives, right-wing terrorism prefers acts such as massacres because acts of extreme violence promote panic and impulsive reactions." The bomb was later found to be composed of 23 kilograms (51 lb) of explosives: 5 kilograms (11 lb) of TNT and Composition B and 18 kilograms (40 lb) of T4 (nitroglycerin for civil use).

Generals Pietro Musumeci, a member of Propaganda Due (P2), and Belmonte of SISMI had a police sergeant put a suitcase full of explosives on a train in Bologna. The suitcase also contained personal items belonging to two right-wing extremists, a Frenchman, and a German. Musumeci also produced a phony dossier, entitled "Terror on trains". He was charged with falsifying evidence to incriminate Roberto Fiore and Gabriele Adinolfi, two leaders of the far-right Terza Posizione who had fled to London. Both Terza Posizione leaders said that Musumeci was trying to divert attention from P2 head Licio Gelli.