The Pearl River Delta (PRD) is the largest megalopolis region in the world, which is located at the estuary of the Pearl River Basin and dominated by sub-tropical and humid monsoon climate. This unique geographical setting makes the PRD highly exposed to pluvial, fluvial and coastal floods. Under climate change, the changes in precipitation regime intensify precipitation extremes, especially at the sub-daily scale, leading to higher risks of pluvial floods in the urban areas and fluvial floods in the riversides. Coastal floods also become more extreme due to the intensification of tropical cyclones and sea level rises. Future projections from CMIP5 Global Climate Models (GCMs) agree on further increases in the risk of these three types of floods, despite the uncertainties in the magnitude of changes. To counter the rising flood threat, PRD cities have adopted various measures to prevent and mitigate flood hazards. Hard measures, such as the three-pronged approach for pluvial flood prevention in Hong Kong and reservoir regulations for fluvial flood prevention for riverside cities, have been successfully implemented. To achieve sustainable flood management for future extreme floods, non-engineering measures should be further improved for playing a more important role in flood warning, prevention and mitigation.