This study examines the ontological status of the concept of the body in Martin Heidegger’s thought and the transformation of this concept between Being and Time (1927) and the Zollikon Seminars (1959–1969). In Being and Time, Heidegger restricts corporeality to a merely spatial reference and excludes the body from phenomenological analysis. This position has led to criticism that he did not assign sufficient importance to the body and even he lacked a deep understanding of its philosophical significance. However, nearly thirty years later, in the Zollikon Seminars, Heidegger returns to the question of corporeality and, in an attempt to transcend current understandings of the body, develops his own conceptualization, differing from the terminology he used in Being and Time. In this context, by referring to the body as the “bodying body/bodying forth” with the concept of “Leiben”, Heidegger aims to move beyond not only the Cartesian mind-body conception but also the Husserlian Leib-Körper distinction. The aim of this study is to argue that Heidegger’s initial silence on the body in Being and Time does not stem from an inability to grasp the significance of corporeality, but rather from a conscious decision to avoid engaging with the issue prematurely through reductive concepts. In this context, we will argue that Heidegger deliberately chose to wait until he had matured enough to develop the concept of Leiben. By articulating the concept of Leiben, Heidegger finds a way to think of the body as one of the essential dimensions of Dasein, as the ground for our understanding of both ourselves and the world. Accordingly, one of the aims of this study is also to elucidate the ontological context of the body’s relation to Being, and to explore how our bodily self-awareness affects the way we perceive the world.