Gymnosphaera is a genus of tree ferns in family Cyatheaceae.
The genus was originally described by Carl Ludwig Blume in 1828. It was frequently treated by later authors as a synonym of Cyathea or Alsophila.
In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Gymnosphaera was left as a synonym of Alsophila, as evidence to support its reliable separation was lacking. More recently, Shi-Yong Dong and collaborators proposed the revival and recircumscription of the genus based on additional phylogenetic evidence, an act subsequently accepted by other tree fern workers.
, the following species are accepted in the genus as currently circumscribed by the Checklist of Ferns and Lycophytes of the World: