In Greek mythology, Laomedon was a Trojan king, son of Ilus, brother of Ganymedes and father of Priam, Astyoche, Lampus, Hicetaon, Clytius, Cilla, Proclia, Aethilla, Clytodora, and Hesione. Tithonus is also described by most sources as Laomedon's eldest legitimate son; and most sources omit Ganymedes from the list of Laomedon's children, but indicate him as his uncle instead. Laomedon's two wives are Strymo (or Rhoeo) and Leucippe; by the former he begot Tithonus and by the latter King Priam (see John Tzetzes' Scholia in Lycophronem 18 («ὁ μὲν γὰρ Πρίαμος ἦν Λευκίππης, ὁ δὲ Τιθωνὸς Ῥοιοῦς ἢ Στρυμοῦς τῆς Σκαμάνδρου θυγατρὸς υἱός»)). He also had a son named Bucolion by the nymph Abarbarea, as recounted by Homer in the Iliad (6.22).
According to one story, Laomedon's son, Ganymedes, was kidnapped by Zeus, who had fallen in love with the beautiful boy. Laomedon grieved for his son. Sympathetic, Zeus sent Hermes with two horses so swift they could run over water. Hermes also assured Laomedon that Ganymedes was immortal and would be the cupbearer for the gods, a position of much distinction. However, Ganymedes is more usually described as a son of Tros, an earlier King of Troy and grandfather of Laomedon. Laomedon himself was son of Ilus, son of Tros.
Poseidon and Apollo, having offended Zeus, were sent to serve King Laomedon. He had them build huge walls around the city and promised to reward them well, a promise he then refused to fulfill. In vengeance, before the Trojan War, Poseidon sent a sea monster to attack Troy.
Laomedon planned on sacrificing his daughter Hesione to Poseidon in the hope of appeasing him. Heracles (along with Oicles and Telamon) rescued her at the last minute and killed the monster. Laomedon had promised them the magic horses as a reward for their deeds, but when he broke his word, Heracles and his allies took vengeance by putting Troy to siege, killing Laomedon and all his sons save Podarces, who saved his own life by giving Heracles a golden veil Hesione had made (and therefore was afterwards called Priam, from priamai 'to buy'). Telamon took Hesione as a war prize and married her; they had a son, Teucer.