Singapore’s corals live in an extreme reef environment characterised by high-sedimentation rates, turbidity and nutrient levels, and low light. Proximity to coastal development and other anthropogenic impacts over several decades has resulted in a compressed zone of coral cover up to 6–7 m depth, beyond which live coral cover declines rapidly, with the benthos primarily composed of rubble and silt. Despite the numerous environmental challenges, Singapore’s remaining reefs still host high coral species diversity and exhibit relatively rapid growth. Here, we review the physiological performance of corals living in such harsh conditions from an energetics approach to shed light on their persistence and provide perspectives on the challenges that could jeopardise their future existence. Past and recent studies on coral photo-physiology, heterotrophy, respiration, growth and reproduction are discussed and synthesised to obtain the daily energy budgets of some common corals from Singapore’s reefs. Overall, corals at shallower reef depths (~2–3 m) showed positive energy balances, while those in deeper waters (~6–7 m) acquired just enough to sustain their daily metabolic needs with little to no scope for growth or reproduction. These findings help explain the current vertical distribution of corals on Singapore’s reefs and underscore the increasing role trophic plasticity is expected to play in the resilience of Singapore’s corals.