In the Iliad Asteropaios (Latin: Asteropaeus) was the leader of the Trojan-allied Paionians along with fellow warrior Pyraechmes. Asteropaios was the son of Pelagon, who was the son of the river god Axios and the mortal woman Periboia. Asteropaios was a newcomer to the war at the start of the Iliad; he had only been in Troy for approximately less than a week.

Asteropaios, (Akessamenos) had the distinction in combat of being ambidextrous and would on occasion throw two spears at once. In BookXII of the Iliad as the Trojans attack the Achaean wall, Asteropaios is a leader of the same division as the Lycian warriors Sarpedon and Glaucus, the division which pressed hard enough to allow Hector and his division breach in the wall.

In book XXI, as Achilles is mercilessly slaughtering Trojan warrior alongside the river Skamandros and polluting the waters with dead bodies (including one of Priam's sons, Lycaon), the river god in turn encourages Asteropaios to make a stand against Achilles.

Achilles and Asteropaios thus engange in one-on-one combat, Asteropaios throwing two spears at the same time at Achilles. One spear hits Achilles' shield, while the other reaches his right forearm and draws blood. Thus, Asteropaios is the only Trojan in the Iliad who was able to draw blood from Achilles. However, he ultimately fails to kill Achilles, and is slain. Later, in the funeral games for the slain Patroclus, the armour of Asteropaios is awarded as prizes.

There is also an asteroid called Asteropaios named after the hero.

The famous allies
Sarpedon led.  He'd chosen to command with him
Glaucus and warlike Asteropaeus, for they seemed
clearly the best of all the others, after himself,
for among them all he was preeminent.
These men linked themselves with sturdy bull's hide shields, 
then in their eagerness made straight for the Danaans.
They thought no one could stop them, as they charged the ships. Iliad Book 12