Hezbollah (; Arabic: حزب الله Ḥizbu 'llāh, lit. 'Party of Allah' or 'Party of God') is a Lebanese Shia Islamist political party and militant group, led since 1992, by its Secretary-General Hassan Nasrallah. Hezbollah's paramilitary wing is the Jihad Council, and its political wing is the Loyalty to the Resistance Bloc party in the Lebanese Parliament.

Hezbollah was established in the wake of the 1982 Lebanon War by Lebanese clerics who had studied in Najaf. It adopted the model set out by Ayatollah Khomeini after the Iranian Revolution in 1979, and the party's founders adopted "Hezbollah" as the name chosen by Khomeini. The organization was created with the support of 1,500 Islamic Revolutionary Guard Corps instructors, and aggregated a variety of Lebanese Shia groups into a unified organization to resist the Israeli occupation of Southern Lebanon. During the Lebanese Civil War, Hezbollah's 1985 manifesto listed its objectives as the expulsion of "the Americans, the French and their allies definitely from Lebanon, putting an end to any colonialist entity on our land". From 1985 to 2000, Hezbollah also participated in the 1985–2000 South Lebanon conflict against the South Lebanon Army (SLA) and Israel Defense Forces (IDF), and fought again with the IDF in the 2006 Lebanon War. Durings the 90s, Hezbollah also organised volunteers to fight for the Army of the Republic of Bosnia and Herzegovina during the Bosnian War.

Since 1990, Hezbollah has participated in Lebanese politics, in a process which is described as the Lebanonisation of Hezbollah, and it later participated in the government of Lebanon and joined political alliances. After the 2006–08 Lebanese protests and clashes, a national unity government was formed in 2008, with Hezbollah and its opposition allies obtaining 11 of 30 cabinet seats, enough to give them veto power. In August 2008, Lebanon's new cabinet unanimously approved a draft policy statement that recognizes Hezbollah's existence as an armed organization and guarantees its right to "liberate or recover occupied lands" (such as the Shebaa Farms). Hezbollah is part of Lebanon's March 8 Alliance, in opposition to the March 14 Alliance. It maintains strong support among Lebanese Shia Muslims, while Sunnis have disagreed with its agenda. Hezbollah also has support in some Christian areas of Lebanon. Since 2012, Hezbollah involvement in the Syrian civil war has seen it join the Syrian government in its fight against the Syrian opposition, which Hezbollah has described as a Zionist plot and a "Wahhabi-Zionist conspiracy" to destroy its alliance with Bashar al-Assad against Israel. Between 2013 and 2015, the organisation deployed its militia in both Syria and Iraq to fight or train local militias to fight against the Islamic State. In the 2018 Lebanese general election, Hezbollah held 12 seats and its alliance won the election by gaining 70 out of 128 seats in the Parliament of Lebanon.

From 2006, the group's military strength grew significantly, to the extent that its paramilitary wing became more powerful than the Lebanese Army. Hezbollah has been described as a "state within a state" and has grown into an organization with seats in the Lebanese government, a radio and a satellite TV station, social services and large-scale military deployment of fighters beyond Lebanon's borders. The group currently receives military training, weapons, and financial support from Iran and political support from Syria, although the sectarian nature of the Syrian war has damaged the group's legitimacy. In 2021, Nasrallah said the group had 100,000 fighters. Either the entire organization or only its military wing has been designated a terrorist organization by several countries, including by the European Union and, since 2017, also by most member states of the Arab League, with two exceptions – Lebanon, where Hezbollah is one of the country's most influential political parties, and Iraq. Russia does not view Hezbollah as a "terrorist organization" but as a "legitimate socio-political force".