Abdera (Greek: Άβδηρα) was a city-state on the coast of Thrace 17 km east-northeast of the mouth of the Nestos, and almost opposite Thasos. The site now lies in the Xanthi regional unit of modern Greece. The municipality of Abdera, or Ávdira (Greek: Άβδηρα, [ˈavðira]), has 18,573 inhabitants (2001). The seat of the municipality is in Genisea.
Its mythical foundation was attributed to Heracles (on behalf of his fallen friend Abderus), its historical one to a colony from Klazomenai. This historical founding was traditionally dated to 654 BC, which is unverified, although evidence in 7th century BC Greek pottery tends to support it. But its prosperity dates from 544 BC, when the majority of the people of Teos (including the poet Anacreon) migrated to Abdera to escape the Persian yoke (Herodotus i.168). The chief coin type, a griffon, is identical with that of Teos; the rich silver coinage is noted for the beauty and variety of its reverse types.
In 513 BC and 512 BC, the Persians conquered Abdera. In 492 BC, the Persians again conquered Abdera, this time under Darius I. It later became part of the Delian League and fought on the side of Athens in the Peloponnesian war.