Tium (Greek: Τῖον) was an ancient settlement, also known as Filyos (Greek: Φίλειος), on the south coast of the Black Sea at the mouth of the river Billaeus[1] in present-day Turkey. Ancient writers variously assigned it to ancient Paphlagonia or Bithynia.

Apart from Tium, Latinized forms of the name are Teium,[2] Tieium and Tius, corresponding to the Greek names Τεῖον (Teion), Τιεῖον (Tieion), Τῖον (Tion) and Τῖος (Tios).[3]