Neoptolemus (/ˌniːəpˈtɒlᵻməs/; Greek: Νεοπτόλεμος, Neoptolemos, "new warrior"), also called Pyrrhus (/ˈpɪrəs/; Πύρρος, Pyrrhos, "red", for his red hair), was the son of the warrior Achilles and the princess Deidamia in Greek mythology, and also the mythical progenitor of the ruling dynasty of the Molossians of ancient Epirus.
In Cypria, Achilles sails to Scyros after a failed exhibition to Troy, marries princess Deidamia and has Neoptolemus, until Achilles is called to arms again. In a non-Homeric version of the story, Achilles' mother Thetis foretold many years before Achilles' birth that there would be a great war. She saw that her only son was to die if he fought in the war. She sought a place for him to avoid fighting in the Trojan War, disguising him as a woman in the court of Lycomedes, the king of Scyros. During that time, he had an affair with the princess, Deidamea, who then gave birth to Neoptolemos. Neoptolemos was originally called Pyrrhos, because his father had taken Pyrrha, the female version of that name, while disguised as a woman.