In Greek Mythology, Aethra was known in four different characters.
- She was the daughter of Pittheus . Pittheus was a king of Troezen. Aethra gave birth to the famous hero Theseus who killed Minotaur with the help of Ariadne. When Aethra’s son, Theseus reached manhood, he and his friend Perithoos kidnapped Helen and gave her to his mother. Aethra guarded Helen while the two men went to the underworld . Helen’s brothers, Castor and Pollux, found Aethra and Helen and rescued Helen. They made Aethra their sister’s slave and then went to Sparta. Later, when Alexandros(also called Paris) took Helen to Troy, Aethra accompanied them. She, along with Helen, went to Troy, until she was rescued by her grandsons(Acamas and Demophon), after the fall of the city.
- Another Aethra was one of the daughters of the Titans Oceanus and Tethys. Sometimes she was called the wife of Atlas and mother of Pleiades, Hyades, and Hyas.
- Aethra, from one source, was called the wife of Hyperion, and mother of Helios, Eos, and Selene
- Aethra was the wife of the Spartan Phalanthus and she fulfilled the prophecy given to her husband by her tears, after which he conquered Tarentum for himself
Aethra was often portrayed in 5th-century-BC art.