Hydrophis sibauensis, also known as the Kalimantan sea snake, is a species of venomous sea snake in the family Elapidae that is native to Indonesia, and endemic to Borneo.

The specific epithet sibauensis refers to the Sibau River.

[3] The range of the snake is limited to the Sibau River, a tributary of the Kapuas River, in West Kalimantan, Borneo, in fresh water some 1,000 km upriver from the sea.

The type locality is Putussibau.

[3] This Elapidae article is a stub.