In Greek mythology, Astraeus or Astraeos (Ancient Greek: Ἀστραῖος) was an astrological deity and the Titan-god of the dusk.
In Hesiod's Theogony and in the Bibliotheca, Astraeus is a second-generation Titan, descended from Crius and Eurybia. However, Hyginus wrote that he was descended directly from Tartarus and Gaia, and referred to him as one of the Gigantes.
Appropriately, as god of the dusk, Astraeus married Eos, goddess of the dawn. Together as nightfall and daybreak they produced many children who are associated with what occurs in the sky during twilight.
They had many sons, the four Anemoi ("Winds"): Boreas, Notus, Eurus, and Zephyrus, and the five Astra Planeta ("Wandering Stars", i.e. planets): Phainon (Saturn), Phaethon (Jupiter), Pyroeis (Mars), Eosphoros/Hesperos (Venus), and Stilbon (Mercury). A few sources mention one daughter, Astraea ("stars", fem. personification. Sometimes: "justice"), but most writers considered Astraea the child of Zeus and Themis.
He is also sometimes associated with Aeolus, the Keeper of the Winds, since winds often swell up around dusk.