This dissertation argues that the political thought of Martin Heidegger and Hannah Arendt is best understood in terms of two fundamental components: namely, a social ontology of the Lebenswelt (or life-world) as well as a normative conception of the individual person. The argument is primarily oriented around the texts of Heidegger and Arendt yet engages significantly with their intellectual milieu in order to resolve interpretive dilemmas.I therefore argue that the work of these two authors can be best understood when seen in the light of philosophical movements such as Lebensphilosophie, phenomenology, and German Existenzphilosophie as well as alongside authors such as Wilhelm Dilthey, George Simmel, Edmund Husserl, Max Scheler, and Karl Jaspers. Through this historical-contextual approach, one can see the systematicity of both Arendt and Heidegger's political thought with greater clarity: both see politics as the practice of properly integrating an authentic individual into a common world of shared social meanings (defined similarly by both).Moreover, once the internal logic of their argument is clarified, I propose that the difference in Heideggerian and Arendtian political thought is primarily due to their different understandings of what constitutes an individual's 'selfhood' or 'personhood'.