Acianthus collinus, commonly known as hooded mosquito orchid or inland mosquito orchid, is a flowering plant in the orchid family Orchidaceae and is endemic to New South Wales and Victoria in Australia. It is a terrestrial herb with a single, heart-shaped leaf and between two and nine translucent pinkish flowers with reddish markings and is found growing in colonies on sheltered slopes in open forest in on the western slopes of the Great Dividing Range.