This thesis analyses a corpus of twenty-first-century British speculative plays in light of utopian studies and deconstruction. My goal is to examine the way contemporary speculative theatre engages with aporia as a mode of utopian thinking and to elucidate the implications of this ‘aporia turn’ on the question of theatre’s social and political commitment. I begin my main analysis with a study of speculative theatre’s mythopoeia, taking into account both specific narratives and the general form of mythical speech. My examination reveals the strategies adopted by speculative theatre to reconfigure and repoliticise myth by resisting its binary logic. This denaturalisation of mythical speech is crucial for the imagination of a radically different form of living-together, which is the focus of the next chapter. Instead of a community based on shared values and similarities, many plays call for a mode of non-hierarchical relationality sustained by nonidentity thinking and resistance against a monologic approach to language. In the last chapter, I will elucidate the dramaturgical strategies employed to generate an aporetic experience that points towards the possibility of a quasi-community of singularities envisioned in the previous chapter. By staging the contemporary Gothic sensibility and the entanglement of space, time, and responsibility, these plays engage the implicated spectator in a rehearsal for change and resistance. I would argue that the space of utopian speculation opened up by contemporary British speculative theatre, permeated with uncertainty and the impossible, is of great political and ethical relevance.