Glaucus (Greek: Γλαῦκος, English translation: "shiny", "bright" or "bluish-green") was a son of Hippolochus and a grandson of Bellerophon. He was a captain in the Lycian army under the command of his close friend and cousin Sarpedon. The Lycians in the Trojan War were allies of Troy. During the war Glaucus fought valiantly, killing four Greeks.
In the Iliad, he met Diomedes in the field of battle in face to face combat. In response to Diomedes' challenge to him, Glaucus said that as a grandson of Bellerophon he would fight anybody. On learning of Glaucus' ancestry Diomedes planted his spear in the ground and told of how his grandfather Oeneus was a close friend of Bellerophon, and declared that the two of them despite being on opposing sides should continue the friendship. As a sign of friendship Diomedes took off his bronze armor worth 9 oxen and gave it to Glaucus. Glaucus then had his wits taken by Zeus and gave Diomedes his gold armor said to be worth 100 oxen.
Glaucus was in the division of Sarpedon and Asteropaios when the Trojans assaulted the Greek wall. Their division fought valiantly, allowing Hector to break through the wall. During this assault Teucer shot Glaucus with an arrow, wounding him and forcing him to withdraw from combat. Later, upon seeing Sarpedon mortally wounded, Glaucus prayed to Apollo, asking him to help him to rescue the body of his dying friend. Apollo cured his wound, allowing Glaucus to rally the Trojans around the body of Sarpedon until the gods carried the body away. Later in the war, when the fighting over Achilles' corpse took place, Glaucus was killed by Ajax. His body, however, was rescued by Aeneas and was then taken by Apollo to Lycia for funeral rites.