Spatial navigation is a promising cognitive marker for several cognitive disorders. However, its clinical utility is still limited because spatial abilities are also influenced by non-pathological factors. Among these, the Cognitive Reserve (CR) stands out due to its strong influence on cognitive aging trajectories. However, the association between CR and spatial navigation across the lifespan has never been assessed. In this study, we collected spatial navigation data along with CR measures in a population with diverse demographic profiles. We found a strong decline in spatial ability with age, but no overall effect of the CR. We systematically analyzed the association between each CR item and spatial ability and found that the subscore related to reading habits was significantly associated with spatial navigation performance, even after correcting for multiple comparisons. We discuss the implications of these findings for early and personalized screening for cognitive disorders using a spatial navigation task.