Gambrium or Gambrion is an ancient city near Kınık and Bergama in İzmir province, in the Aegean Region of Turkey.
It is on a hill named Hisarlık in Bakırçay (ancient Kaikos) valley and very close to modern town of Poyracık.
The name of Gambrium is seen first in the book of Anabasis of Xenophon which gives knowledge about the region in 399 BC. At that time the ruler of the city was Gorgion.
There was a star with twelve rays on the electron money of Gambrium.
- Anabasis, Xenophon, Carleton L.Brownson, Harvard University Press, 1998.
- , Ancient coins of Gambrion
-  Location of Gambrion in ancient Mysia