Teuthrania (Ancient Greek: Τευθρανία) was a town in the western part of ancient Mysia, and the name of its district about the river Caicus, which was believed to be derived from a legendary Mysian king Teuthras.

Demaratus's descendants continued to rule these cities at the beginning of the 4th century BCE.

[5][6] During the withdrawal of Pergamum from The March of the Ten Thousand, it was attacked by, among others, troops from Halisarna and Teuthrania under command of Procles, son of Demaratus.

[7] In the Hellenica, Xenophon relates that Teuthrania, together with Pergamum, Halisarna, Gambrium, Palaegambrium, Myrina and Gryneium were delivered by their rulers to the army that, under the command of the Spartan Thimbron, around the year 399 BCE, had come to the area to try to liberate the Greek colonies from the Persian domain.

[8][9] According to the lost epic poem of the Cypria, Teuthrania was mistaken for Troy in the Achaean’s first expedition to reach the city.