The Armenian genocide was the systematic destruction of the Armenian people and identity in the Ottoman Empire during World War I. Spearheaded by the ruling Committee of Union and Progress (CUP), it was implemented primarily through the mass murder of around one million Armenians during death marches to the Syrian Desert and the forced Islamization of Armenian women and children.

Before World War I, Armenians were concentrated in eastern Anatolia and occupied a protected, but subordinate, place in Ottoman society. Large-scale massacres of Armenians occurred in the 1890s and 1909. The Ottoman Empire suffered a series of military defeats and territorial losses—especially the 1912–1913 Balkan Wars—leading to fear among CUP leaders that the Armenians, whose homeland in the eastern provinces was viewed as the heartland of the Turkish nation, would seek independence. During their invasion of Russian and Persian territory in 1914, Ottoman paramilitaries massacred local Armenians. Ottoman leaders took isolated indications of Armenian resistance as evidence of a widespread rebellion, though no such rebellion existed. Mass deportation was intended to permanently forestall the possibility of Armenian autonomy or independence.

On 24 April 1915, the Ottoman authorities arrested and deported hundreds of Armenian intellectuals and leaders from Constantinople. At the orders of Talaat Pasha, an estimated 800,000 to 1.2 million Armenian women, children, and elderly or infirm people were sent on death marches to the Syrian Desert in 1915 and 1916. Driven forward by paramilitary escorts, the deportees were deprived of food and water and subjected to robbery, rape, and massacres. In the Syrian Desert, the survivors were dispersed into concentration camps. In 1916, another wave of massacres was ordered, leaving about 200,000 deportees alive by the end of 1916. Around 100,000 to 200,000 Armenian women and children were forcibly converted to Islam and integrated into Muslim households. Massacres and ethnic cleansing of Armenian survivors were carried out by the Turkish nationalist movement during the Turkish War of Independence after World War I.

The Armenian genocide resulted in the destruction of more than two millennia of Armenian civilization in eastern Anatolia. Together with the mass murder and expulsion of Syriac and Greek Orthodox Christians, it enabled the creation of an ethnonational Turkish state. The Turkish government maintains that the deportation of Armenians was a legitimate action that cannot be described as genocide. As of 2022, 31 countries have recognized the events as genocide, as do the vast majority of historians.