This research explores the possibility of a phenomenology of religion that is ontological, founded on Martin Heidegger’s philosophical thought. The research attempts to utilise Heidegger’s formulation of phenomenology as ontology while also engaging in a critical relation with his path of thinking; as a barrier to the phenomenological interpretation of the meaning of Religion. This research formulates Religion as an ontological problem wherein the primary question becomes: how are humans, in our being, able to be religious and thus also able to understand the meaning of ‘religion’ or something like ‘religion’? This study focuses on the problem of foundation; of whether it is possible to provide an adequate foundation for the study of religion(s) via the notion ‘Religion’. Further, this study also aims to explore the problem of methodological foundation; of how preconceptions of the meaning of Religion predetermine how religion(s) and religious phenomena are studied. Finally, this research moves toward the possibility of founding a regional ontological basis for the study of religion(s) insofar as the research explores the ontological ground of Religion as a phenomenon. Due to the exploratory and methodological/foundational emphasis of the research, the thesis is almost entirely preliminary. Herein, the research focuses on three main issues: how the notion of Religion is preconceived, how Heidegger’s phenomenology can be tailored to the phenomenon of Religion, and how philosophical thought (in this case, Pre-Socratic philosophy) discloses indications of the meaning of Religion. Pre-Socratic thought is then utilised as a foundation for a preliminary interpretation of how Religion belongs-to humans in our being. This research provides two interrelated theses: the provision of an interpretation of Religion as an existential phenomenon, and an interpretation of Religion in its ground of being-human. With regard to the former, I argue that Religion signifies a potential relation with the ‘originary ground’ of life as meaningful. Accordingly, the second interpretation discloses the meaning of Religion as grounded in being-human; that for humans in our being, the meaning of life is an intrinsic question/dilemma for us. This being-characteristic, I argue, can be called belief.