The Adana massacre (Armenian: Ադանայի կոտորած, Turkish: Adana İğtişaşı) occurred in the Adana Vilayet of the Ottoman Empire in April 1909. A massacre of Armenian Christians by Ottoman Muslims in the city of Adana amidst the Ottoman countercoup of 1909 expanded to a series of anti-Armenian pogroms throughout the province. Around 20,000 to 25,000 people were killed in Adana and surrounding towns, mostly Armenians; it was reported about 1,300 Assyrians were also killed during the massacres. Unlike the earlier Hamidian massacres, the events were not organized by the central government but instead instigated by local officials, intellectuals, and Islamic clerics, including Committee of Union and Progress (CUP) supporters in Adana. Professor of History Ronald Grigor Suny from the University of Michigan describes Adana as "more like an urban riot that degenerated into a pogrom rather than a state-initiated mass killing".Ottoman and Armenian revolutionary groups had cooperated to secure the deposition of Sultan Abdul Hamid II and the restoration of constitutional rule in 1908. In reaction, on 31 March 1909 (13 April by the Western Gregorian calendar) a military revolt directed against the CUP seized Constantinople (Istanbul after 1928). While the revolt lasted only ten days, it precipitated a pogrom and massacres in Adana Province against Armenians that lasted over a month.

The massacres were rooted in political, economic, and religious differences. The Armenian segment of the population of Adana was described as the "richest and most prosperous"; the violence included destruction of "tractors and other kinds of mechanized equipment."