Protobothrops sieversorum, commonly known as the three horned-scaled pit viper or the three-horn-scaled pit viper, is a species of pit viper in the family Viperidae.

The species is endemic to Vietnam and Laos.

Protobothrops sieversorum was originally placed in the monotypic genus Triceratolepidophis.

[3] P. sieversorum is indigenous to the Annamite Mountains of Laos and Vietnam where it has been found in Phong Nha-Ke Bang National Park and the Hin Namno National Biodiversity Conservation Area.

[1] The preferred natural habitat of P. sieversorum is forest, at altitudes of 200–600 m (660–1,970 ft).