Detention is a pressing empirical, conceptual, and political issue. Detained populations, detention facilities, and industries have expanded globally. Detention is also a fundamentally geographical topic, yet largely overlooked by geographers. We argue that detention be conceptualized as a series of geographical processes. Operating through these processes are contradictory sets of temporal and spatial logics that structure the seemingly paradoxical geographies underpinning detention. These logics include containment and mobility, bordering and exclusion. We trace these logics through an emergent literature, synthesizing and analyzing important geographic themes in the field. We identify contributions by and new avenues of inquiry for geographers.