(in order of appearance)
Agamemnon: King of Argos, son of Atreus, general of the Greeks
Old Man: Servant of Agamemnon and Clytemnestra
Chorus: Women from Chalkis, tourists in camp to admire the soldiers
Menelaus: King of Sparta, brother of Agamemnon, son of Atreus, husband of Helen
Clytemnestra: Wife of Agamemnon, mother of Iphigeneia, Electra, and Orestes, sister of Helen
Iphigeneia: Daughter of Agamemnon and Clytemnestra
Achilles: Son of Peleus and Thetis, nearly invulnerable hero of the Greeks
Two Messengers