Ardanuç, Türkiye Cumhuriyeti'nin Karadeniz Bölgesi'nde bulunan Artvin iline bağlı bir ilçe ve ilçenin merkezi olan kasaba.

İlçe toprakları 988 km²'lik bir alanı kaplar.13 Şubat 1921'den 1945 yılına kadar Artvin merkez ilçesine bağlı bir bucaktı. 1 Ağustos 1945 tarih ve 4769 sayılı kanunla ilçe olmuştur. İlk ilçe merkezi Tütünlü iken 1948 yılı Kasım ayında ilçe merkezi Adakale'ye taşınmıştır.

Ardanuç (Georgian: არტანუჯი) is a town and district of Artvin Province in the Black Sea region of Turkey located 32 km east of Artvin.

The history of this area goes back to the settlement of the banks of the Çoruh River by the Hurri and Mitanni branches of the Hittites in 2000 BC. The first mention of Ardanuç was in a Urartu monument to the defeat of the local people in battle by King Sarduri II in 753 BC. Then in the 7th century BC the Saka or Scythians are known to have settled and they dominated Ardanuç. The castle of Artanuji was built by Georgian king Vakhtang Gorgasali (5th century AD).[3] The castle was besieged by Arab caliph Marwan II (688-750) Ummayad in 744 AD. and was restored by Ashot I (Bagrationi dynasty) in the 8th century. He also founded a city, which became the center of the "Kingdom of Georgians" (ქართველთა სამეფო in Georgian) of Tao-Klarjeti.[4][5]

Fighting between the Bagrationi and Anatolian beyliks began in 1080. Ardanuç being a mountain stronghold was hard to capture, although it did fall to the Mongols during their wars with the Turks and Georgians in the 13th century and was brought into the Ottoman Empire in 1551 by Suleiman the Magnificent following yet another siege, this time to overturn the local ruler, Atabeg of Samtskhe Jakeli.

Following the Russo-Turkish War (1877-1878) Ardanuç was ceded to Russia and after the Russian Revolution was returned to the Ottomans and a plebscite was planned to decide its final status.

The short lived, newly independent Democratic Republic of Georgia tried to claim the area but withdrew in 1921. with the Soviet invasion and a petition by the newly formed republic of Turkey.