Haniyeh was born in the al-Shati refugee camp in the then Egyptian-controlled Gaza Strip in 1962 or 1963,[c][10][6][11][12] to parents who were expelled or fled from Al-Jura (now part of Ashkelon) during the 1948 Palestine war.

[5][3][13] He earned a bachelor's degree in Arabic literature from the Islamic University of Gaza in 1987,[13][14] where he first became involved with Hamas, which was formed during the First Intifada against the Israeli occupation.

[15] Haniyeh was head of the Hamas list that won the Palestinian legislative elections of 2006, which campaigned on armed resistance against Israel, and so became Prime Minister of the State of Palestine.

Due to the then-ongoing Fatah–Hamas conflict, Haniyeh did not acknowledge Abbas' decree and continued to exercise prime ministerial authority in the Gaza Strip.

[27][28] Ismail Abdulsalam Ahmed Haniyeh was born to a family of Muslim Palestinians in the al-Shati refugee camp of the Egyptian-occupied Gaza Strip.

[13] Following his release in 1992, the Israeli military authorities of the occupied Palestinian territories exiled him to Lebanon with senior Hamas leaders Abdel-Aziz al-Rantissi, Mahmoud Zahhar, Aziz Duwaik, and 400 other activists.

[13] The activists stayed at Marj al-Zahour in southern Lebanon for over a year, where, according to BBC News, Hamas "received unprecedented media exposure and became known throughout the world".

[32] On the loss of foreign aid from the United States and the European Union, Haniyeh commented that: "The West is always using its donations to apply pressure on the Palestinian people.

On 20 October 2006, on the eve of this deal to end factional fighting between Fatah and Hamas, Haniyeh's convoy came under gunfire in Gaza and one of the cars was set on fire.

Israeli authorities later stated that they would allow Haniyeh to cross the border provided he left the money in Egypt, which would reportedly be transferred to an Arab League bank account.

[40] On 14 June 2007, amid the Battle of Gaza, President Mahmoud Abbas announced the dissolution of the March 2007 unity government and the declaration of a state of emergency.

[21] On 13 October 2016, the Legal Committee of the Palestinian Legislative Council (PLC) endorsed a request for the return of Haniyeh's government to the Gaza Strip, following its resignation on 2 June 2014.

The endorsement was made in response to PLC's review of a study submitted by members of Hamas' parliament, angry about perceived government failings following Haniyeh's resignation.

Despite the PLC recommendation and Hamas' plea, both the consensus government and Fatah refused the request, citing in a press release its illegality and risk of further divisions between Hamas-controlled Gaza and the West Bank.

[47] Haniyeh left Gaza in September to visit a series of Arab and Muslim states in preparation for his new role and officially relocated to the Qatari capital of Doha, where Mashaal has been residing.

[52] Footage from his office in the Qatari capital of Doha showed Haniyeh celebrating the Hamas-led 7 October attack on Israel with other Hamas officials, before they prayed and praised God.

"[55][56] PCPSR opinion poll on Palestinian presidential election candidates[57] On 10 October, Haniyeh said Hamas would not consider the release of any Israeli captives until the war was over.

He claimed that the scope of Israel's retaliation was a reflection of the "resounding impact" the 7 October attack had on the country, and reiterated that the Palestinian people in Gaza had a "willingness to sacrifice all that is precious for the sake of their freedom and dignity."

[60] On 16 October 2023, Haniyeh and Turkey's Foreign Minister Hakan Fidan discussed the possibility of releasing the hostages taken during the Hamas attack on Israel.

On 23 July, a further round of talks between Hamas and Fatah resulted in an agreement to form an “interim national reconciliation government” to maintain Palestinian control in the Gaza Strip after the war.

[17] In March 2002, during the Second Intifada, Haniyeh was quoted as saying, "Jews love life more than any other people, and they prefer not to die," reflecting the view that Palestinian suicide bombings had exposed Israel's greatest vulnerability after years of conflict.

[68] In August 2006, on his first visit abroad as prime minister to Iran, Haniyeh said: "We will never recognize the usurper Zionist government and will continue our jihad-like movement until the liberation of Jerusalem".

[70] On 23 March 2014, during a festival commemorating the tenth anniversary of the assassination of Sheik Ahmad Yassin, Haniyeh delivered a speech to a crowd of Hamas supporters, saying "From within Gaza, I repeat again and again: We will not recognize Israel...

[72] On 2 November 2023, Haniyeh stated that if Israel agreed to a ceasefire and the opening of humanitarian corridors to bring more aid into Gaza, Hamas would be "ready for political negotiations for a two-state solution with Jerusalem as the capital of Palestine," adding that "Israeli captives are subjected to the same destruction and death as our people.

[75] Political analysts said the remarks were an attempt to cool differences in the Gaza Strip with Al-Qaeda-inspired Salafi groups, which condemn Hamas as too moderate.

[79] Haniyeh's sisters, Kholidia, Laila, and Sabah, are Israeli citizens and live in the Bedouin town of Tel as-Sabi in southern Israel.

[83] In October 2014, a few months after the 2014 Israel–Gaza War, Haniyeh's daughter spent a week in an Israeli hospital in Tel Aviv for emergency treatment after she suffered complications from a routine procedure.

[97] Middle East Eye released a video filmed on a mobile phone that allegedly shows one of Haniyeh's granddaughters "moments before fatal Israeli strike", excited about the festivities and yelling, "Eid has come".

According to The New York Times and other sources, Haniyeh was assassinated using a remotely detonated explosive device hidden in his guesthouse room two months earlier, which was triggered once he was confirmed to be inside.

[26][105] The Islamic Revolutionary Guard Corps of Iran said that Haniyeh was killed by "a short-range projectile carrying about 7kg [15.4lb] of explosive materials" that was launched from outside the building he was staying in.