Demaratus of Corinth is a figure known from later historical traditions. Ancient sources, primarily the geographer Strabo, identify him as a Bacchiad noble who fled Corinth during political turmoil and settled in the Etruscan city of Tarquinii. According to these accounts, he brought Greek artisans and cultural knowledge to Italy and was the father of Lucius Tarquinius Priscus, a king of Rome. This narrative places him in the archaic period, specifically the late 7th century BCE, which contradicts some modern scholarly dating to the Hellenistic era.

No literary works by Demaratus survive, nor is he credited with any in the extant sources. His significance lies within Roman foundation myths. Demaratus is portrayed as a key conduit for transmitting Greek culture—including writing, religion, and art—to Etruria and early Rome. This tradition served to legitimize Rome’s cultural origins by connecting them to the Greek world.