Textbook knowledge holds that memory is context-dependent, with similar contexts during encoding and recall facilitating memory performance. However, this does not seem to hold across all memory systems. We asked whether context effects on memory may be mediated by differential consolidation of event-context associations during sleep and wakefulness. Healthy participants performed a cued stimulus-response (S-R) learning task that required speeded object classification. Learning was followed by two hours of either sleep or wakefulness. Testing was conducted in either the same or a different context, with context manipulation involving different labs at different campuses, different experimenters, and different display technology (standard PC screen vs. virtual reality headset). Reaction times revealed stronger S-R memory after sleep than wakefulness with retrieval in the same context, and this benefit was linked to increased sleep spindle activity. In contrast, S-R memory was stronger after wakefulness than sleep when tested in a different context. This wake-dependent enhancement had a fast onset and was reversed by delayed sleep. Our results confirm that sleep strengthens the binding of an event with its context. They further suggest that wakefulness stabilizes event memory per se.