This thesis presents a conceptualization of Arendtian imagination that emerges from an analysis of some of Hannah Arendt's most significant writings. Imagination, on this account, is central to the processes of Arendtian action and Arendtian judgment, insofar as it enables the actor and spectator to imagine a new world that either could look (for the actor) or could have looked (for the spectator) differently from the world that either exists (for the actor) or existed (for the spectator). Importantly, though, the imagined world that facilitates the processes of Arendtian action and Arendtian imagination cannot be so distinct from the world as it exists as to lose any touch with reality itself. Such loss of reality risks actions that are destructive and tyrannical and judgments that are invalid and inattentive. Imagination must be bounded, then, to ensure that the imagined worlds remain close to reality.