The Treaty of Kuchuk-Kainarji (Küçük Kaynarca) was signed on July 21, 1774, between Russia (represented by Field-Marshal Rumyantsev) and the Ottoman Empire after the Ottoman Empire was defeated in the Russo-Turkish War of 1768-1774.

The Ottomans ceded a region between the Dnieper and Southern Bug Rivers to Russia. This territory included the port of Kherson and gave the Russian Empire its first direct access to the Black Sea. The treaty also gave Russia the Crimean ports of Kerch and Enikale and the Kabarda region in the Caucasus.

The Ottomans also lost the Crimean Khanate, which they were forced to grant independance to. The Khanate, while nominally independant, was dependent on Russia and was formally annexed into the Russian Empire in 1783.

The treaty also granted Russia several non-geographic items. It eliminated restrictions over Russian access to the Azov Sea (the 1739 Treaty of Belgrade had given Russia territory adjacent to the Azov Sea but had been prohibited it from fortifying the area or using the sea for shipping.) The treaty also granted Russia some economic and political rights in the Ottoman Empire, such as allowing Ottoman Christians to sail under the Russian flag and providing for the building of a Russian Orthodox Church in Constantinople (which was never built). Russia also interpreted the treaty as giving them the right to protect Orthodox Christians in the Empire.