Bagoas (Old Persian: 𐎲𐎦𐎡 Bagoi, Ancient Greek: Βαγώας Bagōas) was a eunuch in the Persian Empire in the 4th Century BCE, said to have been the catamite of Darius III, and later the Eromenos (Beloved) of Alexander the Great.
The younger Bagoas was a favourite male concubine of Darius III, emperor of Persia. When Darius was murdered by his generals during Alexander's invasion of Persia in 330 BCE, one of the conspirators, Nabarzanes, gave Bagoas to Alexander as a gift. The historian Quintus Curtius Rufus, who wrote a biography of Alexander in the 1st or 2nd Century CE, says that it was Bagoas' pleas that saved Nabarzanes from being killed by Alexander as a regicide.
Curtius relates that Alexander took on "Bagoas, a eunuch exceptional in beauty and in the very flower of boyhood, with whom Darius was intimate and with whom Alexander would later be intimate." (VI.5.23). Bagoas is called Alexander's eromenos ("beloved", a term for a younger male lover) by Curtius – the only person so described.
Their relationship seems to have been well-known and approved among Alexander's troops, as Plutarch recounts an episode (also mentioned by Dicaearchus) during some festivities on the way back from India in which his men clamor for him to openly kiss the young man, who had just won a song and dance contest: "Bagoas...sat down close by him, which so pleased the Macedonians, that they made loud acclamations for him to kiss Bagoas, and never stopped clapping their hands and shouting till Alexander put his arms round him and kissed him."
- Bagoas is the narrator and title character of The Persian Boy, the historical novel by Mary Renault, which portrays him sympathetically. He reappears in a smaller but still significant role in the sequel Funeral Games Funeral Games.
- He makes an even briefer appearance in Les Conquêtes d'Alexandre by Roger Peyrefitte. Peyrefitte, unlike Renault, has Bagoas riding to battle by the side of Darius.
- He is also a major character in Jo Graham's novel Stealing Fire, part of her Numinous World series. Graham's Bagoas is basically the same as Renault's, except that he is more willing to find a new lover after the death of Alexander.
- He is played by Francisco Bosch in the Oliver Stone film Alexander (2004), which is based in part on Renault's writings.
- Athenaeus, Deipnosophistae, xiii; Plutarch, Parallel Lives, "Alexander", 67; Aelian, Varia Historia, iii. 23; Curtius, Historiae Alexandri Magni, vi. 5; x. 1