The Principality of Theodoro, also known as Gothia (Γοτθία) or the Principality of Theodoro-Mangup, was a Greek principality in the southern part of Crimea, specifically on the foothills of the Crimean Mountains. It represented one of the final rump states of the Eastern Roman Empire and the last territorial vestige of the Crimean Goths until its conquest by the Ottoman Empire by the Ottoman Serb Gedik Ahmed Pasha in 1475. Its capital was Doros, also sometimes called Theodoro and now known as Mangup. The state was closely allied with the Empire of Trebizond.

The Crimean Goths were Greuthungi-Gothic tribes or Western Germanic tribes who bore the name Gothi, a title applied to various Germanic tribes who remained in the lands around the Black Sea, especially in Crimea. They were the longest-lasting of the Gothic communities. Their existence is well attested through the ages, though the exact period when they ceased to exist as a distinct culture is unknown; as with the Goths in general, they may have become diffused among the surrounding peoples. In his Fourth Turkish letter, Ogier Ghiselin de Busbecq (1522–1592) describes them as "a warlike people, who to this day inhabit many villages".