Marine heatwaves are driving widespread coral bleaching and mortality, yet substantial variation in bleaching severity and survival often occurs among neighbouring colonies exposed to the same thermal stress. Understanding the ecological factors underpinning this variation is critical for predicting reef resilience and developing effective conservation strategies. We established 60 experimental patch reefs on the northern Great Barrier Reef in November 2022 and tracked Acropora millepora colonies before, during and after the 2023–2024 mass bleaching event. Prior to bleaching, we quantified fish community composition, coral condition, host genetics, Symbiodiniaceae community composition and local environmental conditions across reefs. Substantial variation in bleaching severity and survival was observed among reefs despite exposure to a shared regional heat stress event. Here, I present results of analyses testing whether this variation is explained by differences in pre-disturbance fish communities, coral condition, host genetics, symbiont community composition and local environmental context. The analyses indicate that while pre-disturbance ecological conditions explained significant variation in coral performance, evidence that fish communities directly enhanced bleaching resistance was modest. In contrast, stronger relationships emerged between fish communities and post-bleaching coral growth and persistence, suggesting that the ecological benefits of reef fishes may be expressed primarily during recovery rather than resistance to thermal stress. These findings highlight the importance of considering multiple biological and environmental drivers when assessing coral resilience and suggest that healthy reef fish communities may play a role in supporting coral persistence following increasingly frequent marine heatwaves.