 "Prasophyllum mimulum" was first formally described in 2004 by David Jones from near Lake Baillie in the Central Plateau Conservation Area of Tasmania and the description was published in "The Orchadian".The specific epithet is from the Latin diminutive meaning "imitating" or "mimicking", referring to the overall similarities between this species and "P. alpestre".The highland leek orchid grows in grassland and moorland in subalpine areas of Tasmania.