Muslims in the Ottoman Empire begin a massacre of Armenians in Adana.

The Ottoman Empire, also called the Turkish Empire, was an imperial realm that controlled much of Southeast Europe, West Asia, and North Africa from the 14th to early 20th centuries; it also controlled parts of southeastern Central Europe, between the early 16th and early 18th centuries.

The Adana massacres occurred in the Adana vilayet of the Ottoman Empire in April 1909. Many Armenians were slain by Ottoman Muslims in the city of Adana as the Ottoman countercoup of 1909 triggered a series of pogroms throughout the province. Between 20,000 and 30,000 ethnic Armenians and 1,300 Assyrians were killed and tortured in Adana and the surrounding towns. Unlike the previous Hamidian massacres, the events were not officially organized by the central government, but culturally instigated via local officials, Islamic clerics, and supporters of the Committee of Union and Progress (CUP).

Armenians are an ethnic group indigenous to the Armenian highlands of West Asia. Armenians constitute the main demographic group in Armenia and constituted the main population of the breakaway Republic of Artsakh until their subsequent flight due to the 2023 Azerbaijani offensive. There is a large diaspora of around five million people of Armenian ancestry living outside the Republic of Armenia. The largest Armenian populations exist in Russia, the United States, France, Georgia, Iran, Germany, Ukraine, Lebanon, Brazil, Argentina, Syria, and Turkey. The present-day Armenian diaspora was formed mainly as a result of the Armenian genocide with the exceptions of Iran, former Soviet states, and parts of the Levant.

Adana is a large city in southern Turkey. The city is situated on the Seyhan River, 35 km (22 mi) inland from the northeastern shores of the Mediterranean Sea. It is the administrative seat of the Adana province, and has a population of 1,816,750, making it the largest city in the Mediterranean Region of Turkey.