Gymnoschoenus sphaerocephalus, commonly known as button grass, is a species of tussock-forming sedge from southeastern Australia. It forms part of a unique habitat in Tasmania. It was originally described as Chaetospora sphaerocephala by Scottish botanist Robert Brown in his 1810 work Prodromus Florae Novae Hollandiae et Insulae Van Diemen, before being given its current binomial name in 1858 by Joseph Dalton Hooker. It is also a food item of the critically endangered orange-bellied parrot, which breeds in buttongrass moorlands of southwestern Tasmania over the summer.