In Greek mythology, Iphianassa is an obscure and controversial daughter of Agamemnon, sometimes considered to be identical to Iphigeneia.

Extant plays by Sophocles, Aeschylus and Euripides on the tale of Orestes and Electra do not include her as a character. This is consistent with the theory that she and Iphigeneia are one and the same. On the other hand, Sophocles does mention her, and hints that she lives in the palace of Aegisthus and Clytemnestra, together with Electra and Chrysothemis.