The Khan Shaykhun chemical attack took place on 4 April 2017 on the town of Khan Shaykhun in the Idlib Governorate of Syria. The town was reported to have been struck by an airstrike by government forces followed by massive civilian chemical poisoning. The release of a toxic gas, which included sarin, or a similar substance, killed at least 89 people and injured more than 541, according to the opposition Idlib Health Directorate. The attack was the deadliest use of chemical weapons in the Syrian civil war since the Ghouta chemical attack in 2013.

Idlib Governorate is one of the 14 governorates of Syria. It is situated in northwestern Syria, bordering Turkey's Hatay province to the north, Aleppo Governorate to the east, Hama Governorate to the south, and Latakia Governorate to the west. Reports of its area vary, depending on the source, from 5,933 km2 to 6,097 km2. The provincial capital is Idlib.