The South Lebanon Army or South Lebanese Army, also known as the Lahad Army or as the De Facto Forces (DFF), was a Christian-dominated collaborationist militia in Lebanon. It was founded by Lebanese military officer Saad Haddad in 1977, amidst the Lebanese Civil War, and evolved to operate as a quasi-military during the South Lebanon conflict, basing itself in Haddad's unrecognized State of Free Lebanon.

Saad Haddad was a Lebanese military officer who was the founder and head of the South Lebanon Army (SLA) during the Lebanese Civil War. Originally a Major in the Lebanese Army, he defected and formed the South Lebanon Army and created the separatist State of Free Lebanon backed by Israel. For years Haddad closely collaborated with and received arms and political support from Israel against Lebanese government forces, Hezbollah, and the Syrian Army. Haddad died of cancer in his house in Marjayoun.