Translated by E. Coleridge.
Electra, daughter of Agamemnon and Clytemnestra
Helen, wife of Menelaus
Chorus of Argive Maidens
Orestes, brother of Electra
Menelaus, brother of Agamemnon; King of Argos
Pylades, friend Of Orestes
Messenger, formerly servant of Agamemnon
Hermione, daughter of Menelaus and Helen
A Phrygian Eunuch, in Helen's retinue
Tyndareus, father of Clytemnestra
Before the royal palace at Argos. It is the sixth day after the murder of Clytemnestra and Aegisthus. Electra is discovered alone. Orestes lies sleeping on a couch in the background.
Reference address : https://www.ellopos.net/elpenor/greek-texts/ancient-greece/euripides/orestes.asp