This paper examines the existential themes in Albert Camus’ The Stranger through Martin Heidegger’s philosophy, focusing on concepts such as Being, authenticity, and Being-toward-death from Being and Time. It explores how Meursault, the protagonist, challenges societal norms, reflecting Heidegger’s notion of authenticity while confronting the absurd. By contrasting Heidegger’s existential ontology with Camus’ absurdism, the study highlights their convergences and divergences. Heidegger emphasizes authenticity as acknowledging one’s finitude, while Camus promotes rebellion against life’s absurdity as a path to meaning. The paper explores Heidegger’s ideas of thrownness, anxiety, and the "They," showing their resonance with Meursault’s alienation. Meursault’s ultimate confrontation with death becomes a defining moment, reflecting both Heideggerian authenticity and Camusian acceptance of absurdity. This synthesis provides insights into their philosophical intersections, particularly regarding responses to mortality and societal conformity. While both Camus and Heidegger critique inauthenticity, their approaches to meaning diverge: Heidegger seeks ontological grounding, while Camus focuses on existential defiance. By addressing these complexities, the paper offers a nuanced understanding of existentialism and its application to literature, contributing to broader discussions on Being, freedom, and the human condition.