Cryptostylis, commonly known as the tongue orchid, is a genus of flowering plants from the orchid family, Orchidaceae. It was first defined by the prolific Scottish botanist, Robert Brown in 1810. The type species has since been designated as Cryptostylis erecta. Other species include Cryptostylis hunteriana and Cryptostylis subulata. Molecular study of their DNA shows the genus lies within the tribe Diurideae within the orchid family, having previously considered part of the Cranichideae. Together with the genus Coilochilus they make up the subtribe Cryptostylidinae.