Cyperus breviculmis is a sedge of the family Cyperaceae that is native to parts of northern Australia.
The annual sedge typically grows to a height of with a caespitose habit. The plant blooms between April and August producing green-brown flowers.
In Western Australia it is found around swamps in the Kimberley region where it grows in red-brown permanently damp clay soils. It is also found in the Northern Territory and Queensland.