Jocasta, in Greek mythology, wife of Laius, king of Thebes, and mother of Oedipus, king of Thebes. When an oracle foretold that Jocasta's son would kill his father, Laius had the child's ankles pierced and abandoned him on a mountain.

The infant, rescued by a shepherd and given the name Oedipus, was adopted by Polybus, king of Corinth. Later, when the oracle at Delphi proclaimed that he would kill his father and marry his mother, Oedipus, not wanting any harm to come to Polybus, left Corinth. On the road to Boeotia, Oedipus quarreled with and killed a stranger he mistook for a robber. The victim was his true father, Laius.

Believing her son dead, Jocasta did not recognize Oedipus when he reappeared in Thebes as a young man. The youth saved the city from the sphinx and, as a reward, was married to Jocasta, who bore him four children. When she learned that Oedipus was her son as well as her husband, Jocasta committed suicide in horror and despair at their incestuous relationship.