The kidnapping and murder of Aldo Moro, also referred to in Italy as the Moro case (Italian: caso Moro), was a seminal event in Italian political history. On the morning of 16 March 1978, the day on which a new cabinet led by Giulio Andreotti was to have undergone a confidence vote in the Italian Parliament, the car of Aldo Moro, former prime minister and then president of the Christian Democracy party (Italian: Democrazia Cristiana, or DC, Italy's relative majority party at the time), was assaulted by a group of far-left terrorists known as the Red Brigades (Italian: Brigate Rosse, or BR) in via Fani in Rome. Firing automatic weapons, the terrorists killed Moro's bodyguards — two Carabinieri in Moro's car and three policemen in the following car — and kidnapped him. The events remain a national trauma. Ezio Mauro of La Repubblica described the events as Italy's 9/11. While Italy was not the sole European country to experience extremist terrorism, which also occurred in France, Germany, Ireland, and Spain, the murder of Moro was the apogee of Italy's Years of Lead.

On 9 May 1978, Moro's body was found in the boot of a Renault 4 in via Caetani after 54 days of imprisonment. Moro had been subjected to a political trial by a "people's court" set up by the BR, which had asked the Italian government for an exchange of prisoners. The car with Moro's body was found very close to both locations of the national offices of the DC and the Italian Communist Party (Italian: Partito Comunista Italiano, or PCI, the largest Communist party of Western Europe) in Rome. The BR were opposed to Moro and the PCI's Historic Compromise. On 23 January 1983, an Italian court sentenced 32 members of the BR to life imprisonment for their role in the kidnapping and murder of Moro, among other crimes. Many elements and facts have never been fully cleared up, despite a series of trials, and this has led to the promotion of a number of alternative theories about the events, including conspiracy theories.

The terrorists had prepared an ambush by parking two cars in via Mario Fani that, once moved, would prevent Moro's cars from escaping. According to the official reconstruction at the subsequent trials, eleven people participated in the assault. Other reconstructions report the presence of ten persons, including a lookout, and others mention up to twenty people taking part in the ambush. Doubts have been cast on the terrorists' declarations, which formed the basis for the official accounts, and about the exact identity of the ambush team's members. The presence of Moro himself in via Fani during the ambush has also been questioned following revelations in the 1990s. According to the findings from the judiciary investigations, eleven people took part in the implementation of the plan. The number and the identity of the actual participants has been questioned several times, and even the confessions of the BR have been contradictory on some points.

At 08:45, the BR members took their positions at the end of via Fani, a downhill street in the northern quarter of Rome. Four of them were wearing Alitalia airline crew uniforms. Since not all team members knew each other, the uniforms were needed to avoid friendly fire. In the upper part of the road and on the right-hand side, Mario Moretti was inside a Fiat 128 displaying a fake diplomatic license plate. Alvaro Lojacono and Alessio Casimirri were in another Fiat 128 some meters ahead. On the opposite side of the street, there was a third Fiat 128, with Barbara Balzerani inside, facing the expected direction from which Moro would arrive. Bruno Seghetti [it] occupied a fourth car, a Fiat 132, near the crossroads where the street ended. Moro left his house a few minutes before 09:00 in a blue Fiat 130 driven by Domenico Ricci [it]. Another Carabiniere, the marshal Oreste Leonardi [it], sat beside him. Leonardi was the head of the bodyguard team. The Fiat 130 was followed by a white Alfetta with the three remaining bodyguards: Francesco Zizzi [it], Giulio Rivera [it], and Raffaele Iozzino [it].

The ambush began at 9:00 when the two cars with Moro and his bodyguards entered via Fani. Rita Algranati [it], a lookout posted at the corner of via Trionfale, waved a bunch of flowers to alert the terrorists and then drove off on a moped. Moretti's Fiat 128 swerved into the road in front of Moro's car, which bumped into the rear of Moretti's car and remained blocked between it and the bodyguards' Alfetta. Ricci tried an escape manoeuver but was thwarted by a Mini Minor casually parked at the crossroad. Moro's cars were finally trapped from behind by Lojacono's 128. At this point, four armed terrorists jumped out from the bushes at the sides of the street, firing machine pistols; the judiciary investigations identified them as Valerio Morucci, Raffaele Fiore, Prospero Gallinari, and Franco Bonisoli [it]. This maneuver is similar to one used by the German far-left Red Army Faction (RAF). One unidentified witness declared that a German voice was heard during the ambush, which led to a presumption of the participation of RAF militiamen in the ambush.

At 9:03, an anonymous call to the 1–1–3 emergency service (Polizia di Stato) declared that there had been a shooting in via Fani. 91 bullets were fired, 45 of which hit the bodyguards, who were all killed. 49 shots came from a single weapon, a FNAB-43 submachine gun, and 22 from another of the same model. The remaining 20 shots came from other weapons which included a Beretta M12. Ricci and Leonardi, who were sitting in the front seat of the first car, were killed first. Moro was immediately kidnapped and forced into the Fiat 132, which was next to his car. At the same time, the terrorists shot the other three policemen. The only policeman who was able to shoot back twice was Iozzino; he was immediately hit in the head by Bonisoli. All the guards but Francesco Zizzi, who died in the hospital a few hours later, died at the scene. The blue Fiat 132 was found at 09:40 in via Licinio Calvo with blood stains inside. The other cars used in the ambush were also found in the following days in the same road; according to the declarations of the BR members, the cars had been left in the road that same day.

On 16 March, the escort in via Fani was not carrying weapons, which were instead kept in the boot of the cars; Moro's wife Eleonora Chiavarelli said during the trial that the weapons were in the boot because "these people didn't know how to use weapons because they had never had any shooting practice, they were not used to handling them, so the guns were in the boot. Leonardi always talked about it. 'These people shouldn't have weapons they don't know how to use. They should know how to use them. They should carry them properly. Keep them within reach. The radio should be operational, but it doesn't work.' For months it had been going on like this. Marshal Leonardi and Lance Corporal Ricci did not expect an ambush, because their weapons were placed in the bag and one of the two holsters was even in a plastic liner." Chiavarelli's last statement was disputed by Leonardi's widow, who stated that her husband "recently went around armed because he had noticed that a car was following him." In the procedural documents, there are references to numerous requests from the foreman and from Moro himself for the concession of an armoured car. On 6 December 2017, the latest Massacre Commission stated that an armoured car could have been enough to prevent the via Fani attack.

The Red Brigades claimed responsibility for the attack in a phone call to ANSA. At 10:00, Pietro Ingrao, then-president of Italy's Chamber of Deputies, stopped the parliamentary session and announced that Moro had been kidnapped. In the election on the same day, the fourth Andreotti government received a large majority of votes, including those of his traditional enemies, notably the PCI. Before the kidnapping, the PCI were supposed to enter the government in a direct role but the emergency changed the situation, resulting in another cabinet under the firm control of the DC. The PCI secretary Enrico Berlinguer spoke of "an attempt to stop a positive political process", while Lucio Magri, representative of the Proletarian Unity Party, was concerned about the hypocrisy of passing laws limiting personal freedom as a reaction to the massacre, saying that "it would play into the hands of the strategy of subversion". He asked for introspection from the authorities and for a genuine willingness to tackle problems that, in his own words, "are at the basis of the economic and moral crisis".