in Greek legend, a daughter of Leda and Tyndareus and wife of Agamemnon, commander of the Greek forces in the Trojan War. She took Aegisthus as her lover while Agamemnon was away at war. Upon his return, Clytemnestra and Aegisthus murdered Agamemnon. Clytemnestra was then killed by her son, Orestes, with the help of his sister Electra, in revenge for his father's murder.

In Aeschylus's play Agamemnon (Oresteia), part of his Oresteia trilogy (Oresteia), Clytemnestra is driven to murder Agamemnon partly to avenge the death of her daughter Iphigeneia, whom Agamemnon had sacrificed for the sake of success in the war, partly because of her adulterous love for Aegisthus and partly as an agent for the curse on Agamemnon's family, the House of Atreus. Clytemnestra's story is also told in plays by Sophocles and Euripides.