Israel informed Iran in advance a few hours ahead of the attack of what will be targeted and what will not be, and warned Iran to not respond. The attack involved over 100 aircraft, including F-35 Lightning II stealth fighters, traveling 2,000 kilometres (1,200 mi) and using heavy munitions. A preceding attack on Syria reportedly targeted radar defenses. An Iranian news agency associated with the Islamic Revolutionary Guard Corps reported that military installations in western and southwestern Tehran, as well as bases in the Ilam and Khuzestan provinces, were attacked. Four Iranian Army soldiers were reportedly killed. An Israeli official said that following the strikes targeting Iranian air defence and ballistic missile sites, Israel could now operate with greater freedom in Iranian airspace.

The IDF stated it has completed "precise and targeted strikes" in response to "months of continuous attacks" from Iran and its proxies, as well as a recent barrage of Iranian missiles on Israel on 1 October. US officials confirmed that the US was briefed in advance but did not participate in the operation. Iran quickly aimed to downplay the attacks, providing minimal coverage and threatened to hand out prison sentences to civilians who shared evidence of the strikes to "hostile" media. This was possibly done to "save face" and prevent further escalation.

Iran and Israel have been engaged in a covert conflict for years. Iran has utilized the "Axis of Resistance", a network of Iranian-backed militant groups, to target Israeli interests, while Israel has reportedly carried out assassinations of high-ranking Iranian officials and nuclear scientists and launched cyberattacks against Iran. Israel views Iran as its primary threat due to the Iranian leadership's rhetoric advocating for Israel's destruction, their backing of militant organizations, and the nation's nuclear program. Tensions between the countries have escalated further following Hamas-led 7 October attack on Israel. Following the attack, factions within the "Axis of Resistance," notably Hezbollah in Lebanon and Yemen's Houthi movement, launched assaults on Israel and Red Sea shipping, triggering the Hezbollah-Israel conflict and the Red Sea Crisis. Iran has poured considerable resources into bolstering these groups’ military capabilities and fostering cohesion, aiming for a coordinated Axis effort to dismantle the Jewish state in any large-scale confrontation with Israel.

On 1 April 2024, Israel bombed a consular building in the Iranian embassy complex in Damascus, Syria. The attack killed 16 people, including multiple Iranian officers and proxy fighters. Most notably, Mohammad Reza Zahedi, a commander for the Quds Force, was killed in the airstrike. Iranian officials in the building were allegedly meeting with Palestinian militant leaders at the time of the attack. In response, Iran and its proxies struck Israel on 13 April, targeting military bases. On 19 April, Israel struck an air defense facility in Isfahan, Iran in retaliation. The strikes were limited and de-escalated tensions.

On 31 July, Ismail Haniyeh, the political leader of Hamas, was assassinated in the Iranian capital Tehran by an apparent Israeli attack. Iran vowed to retaliate.

On 17 September, Israel adopted a new war goal: to return civilians displaced by Hezbollah back to their homes in northern Israel. Later that day and the next, thousands of communications devices (including pagers and walkie-talkies) exploded simultaneously across Lebanon and Syria, with Israel aiming to attack Hezbollah members. The attack killed 42 people. In response, Hezbollah launched rocket attacks on northern Israeli cities and towns, including Nazareth, on 22 September. On 23 September, Israel killed two of Hezbollah's top commanders, Ibrahim Aqil and Ahmed Wehbe, in Dahieh, south of Beirut. On 23 September, Israel began a series of strikes in southern Lebanon.

On 27 September, an Israeli airstrike in Dahieh killed Hassan Nasrallah, the secretary-general of Hezbollah. The attack also killed Ali Karaki, the Commander of Hezbollah's Southern Front and Abbas Nilforoushan, deputy commander of the IRGC and commander of the Quds Force in Lebanon.

In response to the killings of Haniyeh, Nilforoushan, and Nasrallah, Iran struck Israel, damaging military bases, in what was the largest attack of the 2024 Iran–Israel conflict. Israel said it had shot down most of the missiles and there had been no harm to its Air Force's capabilities. The US Navy and Jordan also reported intercepting missiles. The two fatalities caused by the attacks were a Palestinian man killed directly by missile debris and an Israeli man indirectly. Israeli Prime Minister Benjamin Netanyahu called it a "big mistake" and vowed that Iran "will pay" for it.

According to US officials speaking anonymously, Israel assured the Biden administration it would refrain from targeting Iran's nuclear and oil facilities, focusing instead on military sites. With the 2024 United States presidential election nearing, American officials worried about being pulled into a wider Middle Eastern conflict. US President Joe Biden asked Netanyahu to plan a retaliation that would "deter further attacks against Israel while reducing risks of further escalation."

In the early hours of 26 October 2024, the Israel Defense Forces (IDF) began conducting airstrikes on military targets in Iran. The IDF stated that the strikes were conducted in response to the October 2024 Iranian strikes against Israel on 1 October and due to militant actions by proxy members of the Axis of Resistance. Just prior to the attacks, Israel notified the United States' Biden administration about the impending attacks on Iran. The strikes continued through the night until dawn in Iran, marking Israel's first openly acknowledged attack on the country. This was the first time since the Iran–Iraq War (1980–1988) that Iran has faced such a prolonged assault from a foreign adversary.

The Jerusalem Post reported that over 100 aircraft, including F-35 Lightning II "Adir" stealth fighters, traveled roughly 2,000 kilometres (1,200 mi) for the attack, deploying heavy munitions with extensive refueling support and the IAF rescue and search force Unit 669 on standby. A preceding operation on radar sites in Syria prevented Iran from gaining intelligence on Israel's intentions.

Beginning at 1:48 a.m. local time, sirens and alarms went off continuously for 30 minutes across the Ankawa neighborhood of Erbil, Iraq, with loudspeakers at Irbil airport's military base repeating the word "bunkers". Iranian State Television issued reports of explosion noises throughout Tehran. Two Arab officials stated that the attack had appeared to target a weapons depot and a military office or barracks. Explosions were also reported in the city of Karaj, located just west of Tehran, and near Imam Khomeini International Airport, Mashhad, Kermanshah, and Zanjan. Explosions were also heard near Damascus, Syria. Al Jazeera posted a video showing Iran's air defense activate in the skies of Tehran. Al Araby TV showed damage from Israeli strikes to a military drone factory in Shamsabad, south of Tehran. Iran later confirmed that strikes had also occurred in Ilam province and Khuzestan.

Yedioth Ahronoth reported that Israel had targeted an Iranian UAV factory as well as a secret base in Tehran. It was also reported that Russian made S-300 Iranian batteries as well as ballistic missile sites were attacked.

According to two Iranian officials, one affiliated with the IRGC, Israel's strikes in Tehran Province targeted key defense sites, including the S-300 air defense system at Imam Khomeini International Airport, which helps protect the capital. The officials reported that multiple IRGC missile bases were hit in the province, followed by a second wave of drone strikes targeting the Parchin military complex on Tehran's outskirts with one drone reportedly reaching the base. The latter site has long been cited by Israel as a site of suspected nuclear weapons-related activity, with the IAEA reportedly finding related evidence there in 2016.

Iranian outlets reported that two Islamic Revolutionary Guard Corps (IRGC) soldiers were killed. Images released by Fars News Agency showed that the soldiers belonged to Iran's Air Defense Force, suggesting that SAM systems were targeted, possibly increasing Iran's vulnerability to future attacks.

At 2:30 a.m., the Israel Defense Forces (IDF) announced it was "conducting precise strikes on military targets in Iran," citing over a year of attacks by Iran and its allies across the Middle East as the reason. According to The New York Times, this statement marked a rare Israeli acknowledgment of military operations within Iranian territory. IDF spokesperson Daniel Hagari said Israel selected these sites from a "broad target bank", and that it would be able to "select additional targets from it and strike them if required", adding that "this is a clear message—those who threaten the State of Israel will pay a heavy price." By around 5 a.m., Israeli officials confirmed that the operation had concluded, with 20 targets struck. The IDF's statement at 6 a.m. confirmed the end of the strikes.

An official from the IDF indicated to Axios that thanks to the attack, Israel now enjoys greater freedom of operation over Iran, in part due to Israel having hit Iranian air defences as well as Iran's ballistic missile infrastructure.

State media confirmed that explosions were heard in Tehran, attributing some of the sounds to air defense systems in the area. However, state television provided no further details for several hours, only briefly mentioning the attack. Reporters stationed throughout the capital presented scenes of normal life, including markets and traffic, suggesting stability after the attack. The IRGC-affiliated channel Tasnim dismissed the attacks as "weak", a response experts described to the BBC as typical for Iran in such situations.

The Iranian government threatened to hand out prison sentences of up to 10 years to civilians who provide evidence on the Israeli airstrikes to media deemed "hostile" by the regime. Foreign Minister Abbas Araghchi stated that Iran has "no limits" when it comes to defending it's interests, territorial integrity, and its people,

Iranian civilians who spoke to The Daily Telegraph expressed concern over continued escalating violence between Israel and Iran.

•  Hamas: The group said it strongly condemned "the Zionist aggression against the Islamic Republic of Iran, and the targeting of military sites in several provinces," adding it was "an escalation that threatens the security of the region."

•  Algeria: The Ministry of Foreign Affairs condemned the military attacks and expressed solidarity with the Iranians.
•  Tunisia: The country issued a statement warning about the consequences of the attack, it also stated to the international community to "urgently assume its responsibilities to put an end to this reckless approach".

•  Malaysia: The Ministry of Foreign Affairs described the strikes as a "clear violation" of international law and called for an "immediate cessation of hostilities".
•  Pakistan: The Foreign Ministry stated that the attacks undermine any chance of peace and stability in the region, it also stated that Israel "bears full responsibility for the current cycle of escalation and expansion of the conflict in the region".

•  France: The Foreign Ministry stated that all parties "must abstain from any escalation and action that could worsen the extremely tense context in the region."
•  Germany: Chancellor Olaf Scholz stated on X that his message to Iran is that "massive escalating reactions must not continue. These must stop immediately. Only then can we open the possibility of a peaceful evolution in the Middle East."
•  Russia: Foreign Ministry spokeswoman Maria Zakharova stated that she urges all parties to "exercise restraint, stop the violence and prevent events from developing into a catastrophic scenario."
•  United Kingdom: Prime Minister Keir Starmer stated in a press conference: "I am clear that Israel has the right to defend itself against Iranian aggression and I am equally clear that we need to avoid further regional escalation and urge all sides to show restraint. Iran should not respond. We will continue to work with allies to de-escalate the situation across the region."

•  Bahrain: The Foreign Ministry has condemned the attack, urging an immediate ceasefire to protect civilians and reduce regional tensions.

•  Egypt: The Foreign Ministry stated that it condemns all actions that threaten the security and stability of the Middle East.
•  Iraq: The Prime Minister's office stated that Israel continues its aggressive policies and expansion of conflict in the region, employing blatant acts of aggression without deterrence. The presidency condemned the Israeli attack, stating it was a flagrant violation of international law and state sovereignty, while reaffirming Iraq's steadfast position against any form of escalation. Government spokesman Basim Alawadi stated that "the occupying Zionist entity continues its aggressive policies and widening the conflict in the region through blatant attacks that it carries out with impunity". Egyptian company Egyptair says it had suspended flights to Baghdad and Erbil.
•  Jordan: The Foreign Ministry stated that the international community "must shoulder it's responsibilities" and take immediate measures to stop the Israeli "aggression" on Gaza, the West Bank and Lebanon as a first step towards reducing the escalation".
•  Kuwait: The Foreign Ministry condemned the attack, stating that the attack reflected the "policy of chaos pursued by the Israeli Occupation Forces through violating the sovereignty of states".
•  Oman: The Foreign Ministry condemned the strikes as a "blatant violation" of Iranian sovereignty.
•  Qatar: The Foreign Ministry called the attacks a "violation of Iran's sovereignty and a clear breach of international law" and further stated that Qatar does not want to see more violence in the region.
•  Saudi Arabia: The Foreign Ministry called the attack a "violation" of Iran's sovereignty and called on both parties to restraint.
•  Syria: The Foreign Ministry expressed its solidarity with Iran, stating that Iran has the "legitimate right to defend itself and protect its territory and the lives of its citizens".
•  Turkey: The Foreign Ministry condemned the attack, stating that Israel will bring the Middle East to a "wider war".
•  United Arab Emirates: The Foreign Ministry condemned the targeting of Iran and expressed deep concern over the continued escalation and its impact on regional security and stability.

•  United States: An unnamed senior official from the Biden administration stated that the airstrikes seem to be a measured and deliberate response to earlier attacks from Iran, posing a minimal risk to civilian safety. National Security Council spokesman Sean Savett said that the Israeli strike "avoided populated areas ... contrary to Iran's attack against Israel that targeted Israel's most populous city." He added that the US urges Iran to stop attacking Israel, "so that this cycle of fighting can end without further escalation."

Defense expert Malcolm Davis told CNN that although Israel's attack was "limited" and "precise," it was "certainly embarrassing" for Iran. He suggested that Iran might hesitate to retaliate, as doing so could provoke Israel to target its nuclear and oil facilities, or even members of Tehran's leadership. Therefore, he argued, Iran may find it wiser to "take this hit and back down."

Iranian-born writer Arash Azizi reported that many Iranians felt "mostly relieved" as Israel's strikes avoided civilian infrastructure like oil refineries, power, and water facilities, as well as political and military officials.

Behnam Ben Taleblu, a Senior Fellow at the Foundation for Defense of Democracies (FDD), observed that Iran appears to be minimizing the impact of the Israeli strike. Iranian state media has refrained from reporting any damage, a move that Taleblu suggests is aimed at controlling public perception and helping the regime maintain its image internally. Jonathan Conricus, also a Senior Fellow at the Foundation for Defense of Democracies, stated that while a comprehensive assessment will depend on satellite analysis in the coming days, it is possible that "Tehran, with all of its regime targets and sensitive infrastructure, might now be totally exposed to future Israeli strikes."

Steven Erlanger argued in an article for The New York Times that Iran faces a difficult choice: while retaliating against Israel risks escalation "when its economy is struggling, its allies are faltering, its military vulnerability is clear and its leadership succession is in play," holding back could suggest weakness to its allies—"badly weakened by the Israeli military's tough response since Oct. 7"—as well as to hardliners at home.