The Israeli–Lebanese conflict, or the South Lebanon conflict, was a series of military clashes involving Israel, Lebanon and Syria, the Palestine Liberation Organization, as well as various militias acting from within Lebanon. The conflict peaked in the 1980s, during the Lebanese Civil War, and has abated since.

The Palestine Liberation Organization (PLO) recruited militants in Lebanon from among the Palestinian refugees who had been expelled or fled after the creation of Israel in 1948. After the PLO leadership and its Fatah brigade were expelled from Jordan in 1970–71 for fomenting a revolt, they entered Southern Lebanon, resulting in an increase of internal and cross-border violence. Meanwhile, demographic tensions over the Lebanese National Pact led to the Lebanese Civil War (1975–1990). PLO actions were one of the key factors in the eruption of the Lebanese Civil War and its bitter battles with Lebanese factions caused foreign intervention. Israel's 1978 invasion of Lebanon pushed the PLO north of the Litani River, but the PLO continued their campaign against Israel. Israel invaded Lebanon again in 1982 in alliance with the major Lebanese Christian militias of the Lebanese Forces and Kataeb Party and forcibly expelled the PLO. In 1983, Israel and Lebanon signed the May 17 Agreement providing a framework for the establishment of normal bilateral relations between the two countries, but relations were disrupted with takeover of Shia and Druze militias in early 1984. Israel withdrew from most of Lebanon in 1985, but kept control of a 19-kilometre (12-mile) security buffer zone, held with the aid of proxy militants in the South Lebanon Army (SLA).

In 1985, Hezbollah, a Lebanese Shia radical movement sponsored by Iran, called for armed struggle to end the Israeli occupation of Lebanese territory. When the Lebanese civil war ended and other warring factions agreed to disarm, Hezbollah and the SLA refused. Combat with Hezbollah weakened Israeli resolve and led to a collapse of the SLA and an Israeli withdrawal in 2000 to their side of the UN designated border.Citing Israeli control of the Shebaa farms territory, Hezbollah continued cross-border attacks intermittently over the next six years. Hezbollah now sought the release of Lebanese citizens in Israeli prisons and successfully used the tactic of capturing Israeli soldiers as leverage for a prisoner exchange in 2004. The capturing of two Israeli soldiers by Hezbollah ignited the 2006 Lebanon War. Its ceasefire called for the disarmament of Hezbollah and the respecting of the territorial integrity and sovereignty of Lebanon by Israel.

Hostilities were suspended on 8 September 2006. As of 2015, the situation has generally remained calm, despite both sides violating the ceasefire agreements; Israel by making near-daily flights over Lebanese territory, and Hezbollah by not disarming.