Allegations have been made that the 2023 Hamas-led attack on Israel constituted a genocidal massacre against Israelis. In the course of the assault, Palestinian militants attacked communities, a music festival, and military bases in the region of southern Israel known as the Gaza Envelope. The attack resulted in the deaths of 1,163 Israelis and foreigners, two thirds of whom were civilians.

Various legal experts and genocide studies scholars cite a multitude of reasonings for their allegation of genocide, including claims that victims were targeted for their Israeli-Jewish identity, that Hamas still adheres to the antisemitic language of its founding charter, or that the alleged intent to destroy the Israeli people "in part" fits the legal definition of genocide. Comparisons of the attack to the Holocaust have been made. Criticisms against the allegation include citing the taking of hostages as proof that there was no genocidal intent, or that the attack was likely intended to kill and instill fear in Israelis, instead of destroy them.

A legal complaint that Hamas committed genocide was brought to the International Criminal Court in November 2023. An ICC arrest warrant for Hamas leader Mohammed Deif claimed that the group committed extermination.

Both Israel and Palestine frequently accuse the other of planning to commit genocide. American counterterrorism analyst Bruce Hoffman, writing for The Atlantic, suggested the attacks were carried out with genocidal intent, pointing to Hamas' founding charter from 1988, which called for the destruction of Israel and featured antisemitic language.

On 7 October 2023, coinciding with the Jewish holiday of Simchat Torah, Hamas launched a surprise attack on Israel from the Gaza Strip. Around 6,000 Palestinians breached the border in 119 places and infiltrated Israel, including 3,800 from the Hamas "elite Nukhba forces" and 2,200 Palestinian civilians and other militants. 1,163 Israelis and foreigners were killed, including 859 civilians, 282 soldiers, 57 policemen and 10 Shin Bet members.

The militants stand accused of various atrocities, including sexual violence. About 250 Israeli civilians and soldiers were also taken as hostages to the Gaza Strip, including 30 kidnapped children. The Hamas assault prompted an Israeli counter-offensive in Gaza. The day is considered the bloodiest in Israel's history and the largest massacre of Jews since the Holocaust.

Al-Qassam militants extensively recorded their actions through body cameras, probably for propaganda purposes. They also stole victims' phones to livestream their deaths on social media. Additionally, they posted messages or media on victims' social media accounts and went as far as calling relatives to taunt them.

Documents discovered on the bodies of Hamas operatives in Israel indicated that carrying out massacres was a key objective of the invasion. Israeli first responders reportedly found instructions on the bodies of the operatives, directing them to target civilian populations, including elementary schools and a youth center, with the explicit order to "kill as many people as possible". The documents also outlined the directive to take hostages for future negotiation purposes.

Ghazi Hamad, a senior Hamas official, stated in a late October 2023 interview that the October 7 attack against Israel was just the beginning. He vowed to launch "a second, a third, a fourth" attack until the country was "annihilated", asserting: "We are victims – everything we do is justified."

On 16 October, an open letter signed by around 240 legal experts, including jurists and academics, declared the Hamas attack on 7 October 2023 as a "crime of genocide". According to the letter, "as these widespread, horrendous acts appear to have been carried out with an intent to destroy, in whole or in part a national group – Israelis – they most probably constitute an international crime of genocide". The letter was endorsed by legal experts from prominent institutions, including Harvard and Columbia Law Schools, King's College London, and the Hebrew University of Jerusalem. Dan Eldad, former acting State Attorney of Israel from February to May 2020, played a key role in drafting the letter. The Raoul Wallenberg Centre for Human Rights, chaired by former Canadian Justice Minister Irwin Cotler, also signed the letter.

Genocide Watch has accused both Hamas and Israel of committing acts of genocide in the Israel-Hamas war. On 17 October 2023, Genocide Watch published a "Genocide Emergency Alert", stating that "Hamas targeted Israelis simply because they were Israelis. It was the deadliest massacre of Jews since the Holocaust. Iran, Hamas, Hezbollah, and Palestinian Islamic Jihad have expressed their genocidal intent to destroy the nation of Israel. The massacres by Hamas constituted acts of genocide. The attacks were also crimes against humanity and war crimes." On 24 October 2023, Genocide Watch issued a new statement. In the statement, scholars of Holocaust studies and genocide studies and prevention, including Gregory H. Stanton and Israel Charny asserted that Hamas' actions against Israeli civilians qualify as genocide and crimes against humanity. The statement calls on the United Nations Human Rights Council, the UN General Assembly, the UN Office of Special Advisors for the Prevention of Genocide, and the UN Security Council to investigate, condemn, and refer the situation to the International Criminal Court (ICC). It also advocates for the recognition of these acts as genocide, crimes against humanity, and war crimes. The call extends to UN member states to use national courts for legal proceedings against those responsible for the genocide.

In an opinion article for The Hill, Arsen Ostrovsky, a human rights lawyer, and Stanislav Pavlovschi, a former judge at the European Court of Human Rights, asserted that Ghazi Hamad's statement that Hamas would repeat the October 7 massacre "again and again" was evidence of the group's genocidal intentions.

American counterterrorism analyst Bruce Hoffman opined that Hamas has consistently maintained genocidal intentions. The Economist has argued that Hamas fighters who conducted the attack on October 7 were carrying out actions in line with their genocidal intentions outlined in the group's founding charter.

In an interview with Al Jazeera in December 2023, former ICC prosecutor Luis Moreno Ocampo said that the attack on October 7 was "probably genocide, because Hamas has intention to destroy Israelis as a group".

Sociologist Martin Shaw viewed Hamas' attack as "a wave of 'genocidal massacres,' localized mass killings whose victims were defined by their Israeli-Jewish identity", adding that the concept of the genocidal massacre, first proposed by Leo Kuper, was "a logical extension of the notion in the convention that genocide can include destroying a group 'in part.'" Stephen D. Smith, a specialist in genocide, also characterized the massacres on October 7 as a genocide. Adam Jones, author of a textbook on genocide, said Hamas' "wild and indiscriminate killing" qualified as a "genocidal massacre" that should be "acknowledged and condemned as such", but the very restrictive intentionality requirement in the legal definition of genocide was still a "high evidentiary bar to reach". Israeli historian and holocaust specialist Raz Segal similarly said: "I definitely see intent to kill a significant number of members of the group, to instill unbelievable trauma and terror among members of the group. But I don't see intent to destroy in relation to the Hamas attack that would render it an act of genocide."

Historian and professor of genocide studies Uğur Ümit Üngör noted that "many commentators rightly pointed out that Hamas committed a genocidal massacre", while also highlighting the killing of Arab Israelis and Bedouins during Hamas' attack as evidence that it may not have been "group selective". He suggested that the attack might fall under the category of "subaltern genocide", drawing comparisons to the mass killing of pied-noirs in Algeria. Political scientist Abdelwahab El-Affendi refuted the "subaltern genocide" thesis, pointing to a "near-consensus" in the field of genocide studies that "genocides are almost invariably perpetrated by states", which does not apply to the Gazan enclave. He stated that the attacks were consistent with terrorism and mass violence, but that the taking of hostages for prisoner exchanges indicated that the intent of the attacks was not genocidal.

British historian Niall Ferguson characterized the events of 7 October as indicative of Hamas' intent to re-enact the Holocaust, and stated that Hamas should be "destroyed" to prevent this. Gideon Greif, a Holocaust historian, drew parallels between the October 7 attacks and the Holocaust in an article for Maariv. He highlighted the infliction of extreme suffering, including immolation, mutation, alleged rape, and the kidnapping of babies; the shared antisemitic hatred between Nazis and Hamas as evident in recorded statements of Hamas operatives proudly announcing the murder of Jews; and the extreme lack of mercy displayed by the attackers.

Israeli historian Havi Dreifuss wrote that "Even though Hamas is unable to replicate the scale of the Holocaust, one cannot ignore the numerous voices that rightly point to experiential elements and ideologies that exhibit similarities", also adding that "These men, women, and children weren't murdered for their actions, but rather, as in the Holocaust, for their very existence."

By contrast, British academic Omar McDoom wrote in the Journal of Genocide Research that comparisons between the Holocaust and 7 October are indicative of a pro-Israel bias in sections of the Holocaust studies community. McDoom argues that the comparison is "problematic" because "the Germans were not an occupied and oppressed people. And Gaza is not a powerful, expansionary state. To the contrary."

In an opinion article for WSJ, Qanta A. Ahmed shared her firsthand experience as a human-rights observer in Israel following the October 7 attacks, branding the assaults by Hamas as a "genocidal massacre", and argued for the attacks to be legally designated as such.

In a December 2023 survey conducted by Harvard CAPS and the Harris Poll, 73% of American respondents viewed Hamas attacks against Jews as genocidal in nature, and 74% believed that Hamas harbored intentions of committing genocide against Jews in Israel.

John Kirby, US National Security Council Coordinator for Strategic Communications, accused Hamas of "genocidal intentions against the people of Israel. They would like to see it wiped off the map, they said so on purpose. And they've said that they're not going to stop. What happened on the 7th of October is going to happen again and again and again. And what happened on the 7th of October? Murder; slaughter of innocent people in their homes or at a music festival. That's genocidal intentions."

At the UN's European headquarters, Yeela Cytrin, a legal advisor at the Mission of Israel to the UN in Geneva, emphasized: "The attacks by Hamas on October 7 were motivated by a genocidal ideology."

In November 2023, French diplomat and lawyer François Zimeray, representing the families of nine Israeli victims of the 7 October Hamas attacks, filed a complaint at the International Criminal Court (ICC) accusing Hamas of genocide. Zimeray affirmed that he and his legal team had verified the legitimacy of the "genocide" accusation in accordance with the law.

In February 2024, a separate complaint was filed with the ICC by a delegation of family members of Israeli hostages being held in Gaza, accusing Hamas of committing war crimes. The head of the legal team, Shelly Yeviv Aini, stated that "these crimes, including genocide, hostage taking, enforced disappearance, torture and sexual violence cannot and should not go unpunished".

• Gaza genocide
• Palestinian genocide accusation
• Sexual and gender-based violence in the 7 October attack on Israel
• Sexual and gender-based violence in 2023 Israeli attack on Gaza
• War and genocide