Throughout their range, giant clams (family Cardiidae, subfamily Tridacninae) are increasingly threatened by anthropogenic impacts and natural disasters. While almost all tridacnid species are protected under Appendix II of CITES and included in the IUCN Red Data List, these classifications are outdated and may not accurately reflect the situation in individual countries. Recent extensive surveys and a literature review established that the coral reefs in Singapore host two genera and five species of giant clams. Their present conservation status is herein evaluated, and we propose that all are highly threatened in Singapore: Tridacna maxima and Tridacna squamosa are ―critically endangered‖, and Tridacna crocea is ―endangered‖, while Hippopus hippopus and Tridacna gigas are ―presumed nationally extinct‖. Species assessments at finer geographical scales provide a more nuanced status and are therefore of greater value when planning local conservation strategies. As Singapore‘s reefs continue to undergo coastal modifications, active management of the remaining giant clam species is necessary to prevent their extirpation.