The end of the twentieth century and the beginning of the twenty-first have witnessed the rise of significant philosophical movements known collectively as “posthumanism,” the most prominent of which are “transhumanism” and “critical posthumanism.” Though their emphases and details differ, they are united in rejecting traditional philosophical anthropologies which posit a universal “human nature” with fixed essential contents. Phenomenology is an extraordinarily influential philosophical methodology founded by Edmund Husserl (1859–1938) and initially developed by Martin Heidegger (1889–1976), Jean-Paul Sartre (1905–1980), Maurice Merleau-Ponty (1908–1961), and others. This chapter contextualizes posthumanism, provides a substantive historical explication of the phenomenological tradition, and addresses the question of why phenomenology is the philosophical methodology best suited to discussing issues of posthumanism.