The reptilian fauna of Sinharaja is represented by 45 species, of while 21 are endemic. This includes a large proportion of snakes, several lizards, tortoises and skinks.

Among the venomous species that occur in the forest are the Green-pitviper while is arboreal, the Hump-nosed Viper and the Krait while frequents the forest floor. The Cobra is seen occasionally while the Russel's Viper has been observed in secondary vegetation, although not seen in the undisturbed forest.

Green-pit Viper(Trimerasurus trinoncephalus)

Merrem's Hump-nosed Viper(Hypnale hypnale)

Great Forest Gecko(Gymnodactylus frenatus)

Jungle Gecko(Cnemaspis kandianus)

Rat-snake Skink(Mabuya carinata)

Spotted Skink(Mabuya macularia)

Smooth Skink(Sphenomorphus taprobanensis)