Siamese crocodile (Crocodylus siamensis) is a freshwater crocodile native to Indonesia (Borneo and possibly Java), Brunei, East Malaysia, Laos, Cambodia, Burma, Thailand, and Vietnam. The species is critically endangered and already extirpated from many regions. Its other common names include: Siamese freshwater crocodile, Singapore small-grain, cocodrilo de Siam, crocodile du Siam, buaja, buaya kodok, jara kaenumchued, and soft-belly.

The Siamese crocodile is a small, freshwater crocodilian (a group that also includes alligators, caimans and the gharial), with a relatively broad, smooth snout and an elevated, bony crest behind each eye. It is one of the most endangered crocodiles in the wild, although it is extensively bred in captivity.

The historic range of the Siamese crocodile included most of Southeast Asia. This species is now extinct in the wild or nearly extinct from most countries except Cambodia. Formerly it was found in Cambodia, Indonesia (Borneo and possibly Java), Laos, Malaysia, Thailand, Vietnam, Brunei, and Burma.