Oedipus the King (often known by the Latin title Oedipus Rex) is an Athenian tragedy by Sophocles that was first performed c. 429 BC. It was the second of Sophocles's three Theban plays to be produced, but it comes first in the internal chronology, followed by Oedipus at Colonus and then Antigone. Over the centuries, it has come to be regarded by many as the Greek tragedy par excellence.

This is the final installment in Sophocles's Theban Plays, following Oedipus Rex and Oedipus at Colonus. Oedipus's daughter Antigone deliberately breaks the laws of Thebes when she buries her brother's body and is sentenced to death. She clashes with Creon, the King of Thebes, over what constitutes justice and morality: the laws of the state or the laws of the individual.

This is the second installment in Sophocles's Theban Plays that chronicles the tragic fates of Oedipus and his family. After fulfilling the prophecy that predicted he would kill his father and marry his mother, Oedipus blinds himself and leaves Thebes, to wander in the wilderness accompanied by his daughters Antigone and Ismene.

Sophocles' play dramatizes the aftermath of Agamemnon's murder by his wife Clytemnestra and her lover Aegisthus. His daughter Electra is hungry for revenge and longs for the return of her brother Orestes to help her achieve her ends.

Sophocles' play recounts an episode from the Trojan War, in which the wily Odysseus and Achilles' son Neoptolemus travel to a remote island to persuade Philoctetes to come with them to Troy. A prophet has foreseen that the Greeks will need Philoctetes and his bow (given to him by Heracles before his death) in order to defeat the Trojans. The problem is that years before Odysseus had engineered Philoctetes' abandonment on the island, due to a festering, stinking wound he had received from a snakebite. Will Philoctetes forgive and forget, or will he take his revenge?

Traducidas al castellano por José Alemany Bolufer, en esta edición de 1921, se ofrecen "juntas en un tomo y vertidas del original griego" las siete tragedias de Sófocles: Áyax, Electra, Edipo Rey, Edipo En Colono, Antígona, Las Traquinias y Filoctetes.De hecho, son las únicas que se han conservado de las 123 que se le atribuyen. Sófocles, se sitúa, junto con Esquilo y Eurípides, entre las figuras más destacadas de la tragedia griega.