In Greek mythology, Astymedusa (Ancient Greek: Ἀστυμέδουσα, Astymédousa) or simply Medusa, was a Mycenaean princess as daughter of King Sthenelus and Nicippe, daughter of Pelops.

She was occasionally named as a later wife of Oedipus. After parting with Jocasta or after the death of Euryganeia, who was his second wife,^[1] Oedipus married Astymedousa.^[2] Astymedusa accused Polynices and Eteocles of attempting to rape her, thus driving Oedipus into a frenzy.^[3] This is held as an alternate cause for the curse which led to the fraternal discord at the heart of the myth of the wars at Thebes.^[4]