On the morning of 29 October 2020, three people were killed in a stabbing attack at Notre-Dame de Nice, a Roman Catholic basilica in Nice, France. The attacker, Tunisian man Brahim Aouissaoui, was shot by the police and taken into custody. He was convicted and sentenced to life imprisonment in 2025.

Both French President Emmanuel Macron and the mayor of Nice, Christian Estrosi, said it was a terrorist attack attributed to Islamic extremism.

In recent years, France has seen many jihadist terrorist attacks, carried out by both Islamic State and Al-Qaeda terrorist cells, and by lone-wolf terrorists. Nice was the scene of a truck attack in 2016, which resulted in the deaths of 86 people. Four weeks prior to this attack, French President Emmanuel Macron described Islam as a religion "in crisis" worldwide, prompting backlash from Muslims. He vowed to present a bill to strengthen a 1905 law that officially separated church and state in France. Two weeks later, Samuel Paty, a history teacher, was accused by an unnamed student of showing his classes offensive Charlie Hebdo cartoons depicting the Islamic prophet Muhammad. The student who provided the original account of Paty's lesson was, in fact, a truant. She later admitted to lying about being present and having exaggerating others' accounts in order to blame Paty for her recent suspension from school.

Despite this, her account incited anger among the Islamic community in France and eventually led to the murder and beheading of Paty in the Île-de-France by an 18-year-old Chechen Muslim who had acquired refugee status in France in March 2020. The female student's father had reportedly issued a fatwa against Paty based on his daughter's account. After Paty's murder, Macron defended the publication of cartoons depicting Muhammad on free speech grounds. Following these events, and Macron's defence of the cartoons in particular, Turkish President Recep Tayyip Erdoğan called for a boycott of French products. Several protests across the Muslim world followed, in which photographs of Macron were burned, accompanied by anti-French chants.

The attack occurred on 29 October 2020 at 8:30 CET (7:30 GMT), in the premises of Notre-Dame de Nice, a Roman Catholic basilica situated on the Avenue Jean Médecin in the centre of Nice. The attacker killed three people with a knife. One victim, a 60 year-old woman, received a "very deep throat cut like a decapitation". Another was the sexton of the church, and the third victim was another woman.

The attack was carried out over a span of 28 minutes, during which he shouted "Allahu Akbar," repeatedly. Four responding police officers first tasered the attacker and then shot him, even as he continued to shout, "Allahu Akbar!" The suspect was then taken to hospital, where he was in life-threatening condition. A total of 14 shots were fired by police. Authorities found items that they said belonged to the suspect, including a Quran, three knives, and two cell phones.

Interior Minister Gérald Darmanin said immediately after that a police operation was underway in the city. A bomb disposal unit responded to the crime scene, while heavily armed anti-terror police officers patrolled the streets around the basilica.

In the days after the attack, police arrested two men who were believed to have been in contact with the attacker immediately prior to the incident.