Sharp wave-ripple complexes (SW-Rs), a transient form of high-frequency field oscillations observed in the hippocampus, are thought to mediate memory consolidation. They are initiated mainly in the hippocampal CA3 area and propagate to the entorhinal cortex through the subiculum; however, little is known about how SW-Rs are initiated and propagate at the cellular level. Here, we used functional multineuronal calcium imaging to monitor SW-R-relevant neuronal activity from the subiculum at single-cell resolution. An unexpected finding was that a subset of subicular neurons was activated immediately before hippocampal SW-Rs. The SW-R-preceding activity was not abolished by surgical lesion of the CA1-to-subiculum projection, and thus, it probably arose from entorhinal inputs. Therefore, SW-Rs are likely to be triggered by entorhinal-to-CA3/CA1 inputs. We discovered that SW-R-related neurons in the subiculum can be classified into SW-R-preceding and SW-R-following neurons. Therefore, the subiculum is likely to contribute both to the generation and propagation of SW-Rs, although it was previously believed to simply relay hippocampal SW-Rs to the entorhinal cortex. Moreover, neurons that were biphasically activated before and after SW-Rs, even though they were numerically less dominant, existed in the subiculum, suggesting that the subiculum is not merely a passive intermediate region that SW-Rs pass through, but rather, it seems to contribute to an active modification of neural information related to SW-Rs.