Cyperus gilesii, commonly known as Giles' flat-sedge,[1] is a sedge of the Cyperaceae that is native to Australia.

The sedge flowers in spring and summer producing simple inflorescences with one to five branches that have a length of around 6 cm (2.4 in).

The dense flower clusters are subdigitate with a hemispherical to globose shape and a diameter of around 50 mm (2.0 in).

[2][1] The species was first formally described by the botanist George Bentham in 1878 in the work Flora Australiensis.

[3] The specific epithet honours the explorer William Ernest Powell Giles who led five major expeditions throughout central Australia.