The partition of the Ottoman Empire was a geopolitical event that occurred after World War I and the occupation of Constantinople by British, French, and Italian troops in November 1918. The partitioning was planned in several agreements made by the Allied Powers early in the course of World War I, notably the Sykes–Picot Agreement, after the Ottoman Empire had joined Germany to form the Ottoman–German Alliance. The huge conglomeration of territories and peoples that formerly comprised the Ottoman Empire was divided into several new states. The Ottoman Empire had been the leading Islamic state in geopolitical, cultural and ideological terms. The partitioning of the Ottoman Empire after the war led to the domination of the Middle East by Western powers such as Britain and France, and saw the creation of the modern Arab world and the Republic of Turkey. Resistance to the influence of these powers came from the Turkish National Movement but did not become widespread in the other post-Ottoman states until the period of rapid decolonization after World War II.

The occupation of Istanbul or occupation of Constantinople, the capital of the Ottoman Empire, by British, French, Italian, and Greek forces, took place in accordance with the Armistice of Mudros, which ended Ottoman participation in the First World War. The first French troops entered the city on 12 November 1918, followed by British troops the next day. The Italian troops landed in Galata on 7 February 1919.