This article argues that Giovanni’s Room can be read as James Baldwin’s response to European existentialist thought, particularly regarding their differing views of self-transformation and the pivotal role of the sexually desiring body in this process. Comparing Baldwin’s novel to Albert Camus’s The Stranger and to Jean-Paul Sartre’s Being and Nothingness, the article identifies three key divergences. First, Baldwin shifts the narrative focus from the condemned man to his lover, revealing the limits of existentialist philosophy’s individualist focus. Second, Baldwin challenges existentialism’s characteristic pessimism by portraying the capacity to overcome shame and self-deception—Sartrean “bad faith”—to pursue a more authentic existence. Third, Baldwin underscores the desiring body’s role in this transformation. By exploring these three dimensions, the article contributes to the ongoing effort to recognize in Baldwin not only an artist and a keen political commentator but also a deeply philosophical thinker.