In Greek mythology, Laomedon (/leɪˈɒmɪdɒn/; Ancient Greek: Λαομέδων, Lāomédōn, "ruler of the people") was a Trojan king, son of Ilus and thus nephew of Ganymede and Assaracus.

Laomedon was variously identified with different parents and siblings, as well as numerous children, including Priam and Tithonus. His possible wives were Placia, Strymo, Zeuxippe, or Leucippe. Laomedon owned magical horses with divine parentage, a gift from Zeus to his grandfather Tros in compensation for kidnapping Tros's son Ganymede.

Zeus sent Poseidon and Apollo to serve Laomedon as punishment for a conspiracy against Zeus. The two gods built walls around Troy, but Laomedon refused to pay them, leading to a pestilence and a sea monster attacking the city. To end the calamities, Laomedon had to sacrifice his daughter Hesione to the sea monster. Heracles arrived and agreed to save Hesione in exchange for the magical horses, but Laomedon went back on his promise, causing Heracles to wage war on Troy.

Heracles eventually conquered the city, killing Laomedon and his sons, except for Podarces. Hesione was given to Telamon as a war prize, and she ransomed her brother Podarces, who then became known as Priam.

Laomedon's mother was variously identified as Eurydice, Leucippe or Batia. Thus, his possible siblings are Themiste, Telecleia and sometimes, even Tithonus.

He was the father of Priam, Lampus, Hicetaon, Clytius, Hesione, Cilla, Astyoche, Proclia, Aethilla, Medesicaste and Clytodora. Tithonus is also described by most sources as Laomedon's eldest legitimate son, and most sources omit Ganymede from the list of Laomedon's children, but indicate him as his uncle instead. Laomedon's possible wives were Placia, Strymo (or Rhoeo), Zeuxippe or Leucippe; by the former he begot Tithonus and by the latter King Priam («ὁ μὲν γὰρ Πρίαμος ἦν Λευκίππης, ὁ δὲ Τιθωνὸς Ῥοιοῦς ἢ Στρυμοῦς τῆς Σκαμάνδρου θυγατρὸς υἱός»: "Priamus was the son of Leucippe, whereas Tithonus was the son of Rhoeo or Strymo, the daughter of Scamander". He also had a son named Bucolion by the nymph Calybe, as recounted by Homer in the Iliad. Dictys Cretensis added Thymoetes to the list of Laomedon's children.

Laomedon owned several horses with divine parentage that Zeus had given Tros (Laomedon's grandfather) as compensation for the kidnapping of Tros's son Ganymede. Anchises secretly bred his own mares from these horses.

According to one story, Ganymede was kidnapped by Zeus, who had seen the exceptional Virtue of the boy, as worthy only of Olympus, and ascended the young man into Heaven. Tros grieved for his son. Sympathetic, Zeus sent Hermes with two horses so swift they could run over water. Hermes also assured Tros that Ganymede was immortal and would be the cupbearer for the gods, a position of much distinction. Laomedon himself was the son of Ganymede's brother Ilus, the son of Tros.