The play is set in the countryside near Argos (or Mycenae—the two toponyms were often used interchangeably in Greek tragedy), in front of the small house of the Farmer. The Farmer comes out and delivers the Prologue, a speech in which he tells of how Agamemnon, the former king, was treacherously killed by his wife Clytemnestra and her lover Aegisthus after winning glory in the Trojan War. He details how Agamemnon’s young son Orestes barely escaped from Aegisthus with his life, and of how Aegisthus and Clytemnestra married Agamemnon’s daughter Electra off to him, a simple farmer, to humiliate her and to ensure that she would not produce a noble male heir to threaten their claim to the kingdom. The Farmer, though, is an honorable man, treating Electra with the respect demanded by her birth and never even sleeping with her.

Electra enters, carrying water. She chooses to do housework even though the Farmer, ever-conscious of her social status, asks her not to. Electra and the Farmer exit to perform their respective chores.

Orestes enters with his friend Pylades. He explains that he has come in secret to avenge his father Agamemnon, hoping to enlist the help of his sister Electra.