In my examination of Sophocles’ Antigone, I use Beauvoir’s existential philosophy as a lens and hermeneutic model and apply her language and terms—immanence, transcendence, and ambiguity—to the original ancient text to understand the gendered metaphors of the play and to reveal an area of oversight in her superficial treatment of the tragedy. Taking this theoretical approach, I use “feminist” or “existentialist” Beauvoir (The ethics of ambiguity, The second sex) against herself, that is, her interpretation of the Antigone in “Moral idealism and political realism,” to show how existentialist freedom is achieved in the tragedy. In my reading, I cast Antigone as a figure of ambiguity, situated in an oppressive context, and I argue that she creates her own project and strives towards freedom, in the Beauvoirian sense. I also extend the subjectivity of ambiguity to Ismene and illustrate the course of her own existential freedom to portray the reversibility of the transcendence/immanence polarity in these two figures and, ultimately, to suggest that the sisters are intertwined. Inscribing my reading in a tradition of feminist interpretations surrounding the Antigone, I advance a new reading that finds in the play a feminist political theory of existentialism, inclusive of the sororal pair.