Tropidophorus matsuii, also known commonly as Matsui's water skink, is a species of lizard in the subfamily Sphenomorphinae of the family Scincidae. The species is endemic to Thailand.
The specific name, matsuii, is in honor of Japanese herpetologist .
Tropidophorus matsuii is found in northeastern Thailand, in Roi Et province.
The preferred natural habitats of Tropidophorus matsuii are forest and freshwater wetlands, at altitudes of approximately .
Tropidophorus matsuii is semiaquatic.
Tropidophorus matsuii is ovoviviparous.