This study aims to examine posthuman aesthetics in Virginia Woolf’s novels, The Waves and Orlando, based on agential realism which is a posthumanist performative account proposed by new materialism feminist Karen Barad. The lives of Bernard and Orlando in these novels personify the ontology of agential realism. Woolf presents new kinds of bodily aesthetics emerging from relational ontology and ontological inseparability such as the body of viscous porosity, and of brittlestar constantly changing its bodily boundaries through intra-acting with the environment. The Waves and Orlando are abundant with aesthetics of phenomena, of diffraction, and of entanglements, in all of which human and nonhuman agencies are inseparably entangled and dynamically intra-acting. Woolf makes persons, things, and events emerge only as phenomena, not distinct entities. As Bernard in The Waves says he is made and remade continually, human subjects and human bodies are iteratively reconfigured through the material-discursive practices. Orlando’s gender-changing, four-century-long life dramatizes the idea that subject, temporality and spatiality are intra-actively produced. This embodies Woolf’s optimistic posthuman vision in accord with Barad’s belief that humans are part of the world in its open-ended becoming, the future is radically open, and the past and the future are iteratively reconfigured through one another.