Pterostylis sargentii commonly known as the frog greenhood, is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It is a relatively common orchid which has up to six relatively small, white flowers with green or brown stripes and a fleshy, three-part, frog-like labellum. Non-flowering plants have a rosette of leaves on a short stalk.