Protobothrops cornutus, commonly known as the horned pit viper[1] or Fan-Si-Pan horned pit viper,[3] is a pit viper species found in northern and central Vietnam and in southern China (Guangdong).

[2] The type locality given is "Fan-si-pan mountains, Tonkin, Indo-China"[2][4] (=Mount Fansipan).

[1] The only Chinese record is from Ruyuan Yao Autonomous County in northern Guangdong and was originally described as a new species, Ceratrimeresurus shenlii.

[1][2] It occurs in evergreen forest on both karst and granitic outcrops at elevations of 250–2,000 m (820–6,560 ft) above sea level.

[1] Herrmann et al. (2004) moved this species to the genus Protobothrops based on external and hemipenal morphology, as well as molecular data.