Several deities in Greek mythology possessed the name Glaucus.

He was a minor god of the sea endowed with the gift of prophecy. In the story of Jason and the Argonauts, Glaucus bids Jason and his crew to leave Heracles in the bay of Bithynia where the city of Cius lies on the grounds that Zeus had other plans for Heracles. Glaucus was also the grandson of Bellerophon and Lycian prince. In the Trojan war he was allied to Troy and fell at the hands of Ajax in battle.