Kaynardzha (also transliterated as Kajnardža; Bulgarian: Кайнарджа, IPA: [kɐjnɐrˈd͡ʒa]; Romanian: Cainargeaua Mică; Turkish: Kaynarca; Greek: Καϊναρτζή) is a village in northeastern Bulgaria, part of Silistra Province. It is the administrative centre of Kaynardzha Municipality, which lies in the easternmost part of Silistra Province, in the historical region of Southern Dobruja, close to the Romanian border.
The village is known as the location of the signing of the Treaty of Küçük Kaynarca on 21 July 1774 between Count Pyotr Rumyantsev, representative of Empress Catherine the Great of the Russian Empire and Musul Zade Mehmed Pasha, representative of Sultan Abdul Hamid I of the Ottoman Empire. The treaty put an end to the Russo-Turkish War of 1768–1774, which was devastating for the once-mighty Ottoman realm.