Gymnoschoenus sphaerocephalus, commonly known as buttongrass, is a species of tussock-forming sedge from southeastern Australia.

[2] It was originally described as Chaetospora sphaerocephala by Scottish botanist Robert Brown in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen,[3] before being given its current binomial name in 1858 by Joseph Dalton Hooker.

[2] G. sphaerocephalus grows in damp nutrient-poor soils, and in Tasmania forms a low grassland or moor in which it is the dominant shrub.

Associated primitive plants include club mosses such as Lycopodiella lateralis, and Selaginella uliginosa and the ferns Gleichenia dicarpa and G. alpina.

[5] It is also a food item of the critically endangered orange-bellied parrot, which breeds in buttongrass moorlands of southwestern Tasmania over the summer.