It is the goal of this article to present and discuss the phenomenological interpretation of quantum mechanics of the twentieth-century Spanish philosopher Xavier Zubiri. After presenting an introduction to Zubiri and his relationship with phenomenology, we discuss the prominent role of the natural sciences, namely, physics, in the author’s philosophical system. To a certain extent, one can say that, in the footsteps of Edmund Husserl, one of Zubiri’s chief concerns was to develop a philosophical system that could accommodate the discoveries of contemporary science. Following a brief presentation of Zubiri’s discussion on physics, the article focuses on his interpretation of quantum mechanics. As we shall see, Zubiri’s original interpretation of Heisenberg’s uncertainty principle in terms of the phenomenological notion of light may provide a significant, although limited, contribution for a deeper understanding of quantum indeterminacy. In addition, we suggest that the Zubirian notions of reality, intelligence, and actuality, which dominate the last stage of his philosophy, may provide a key hermeneutic framework that allows a fresh philosophical interpretation of quantum mechanics.