Leucopogon extremus is a species of flowering plant in the heath family Ericaceae and is endemic to a restricted part of the Jarrah Forest bioregion in the south-west of Western Australia. It is a shrub with "remarkably anomalous morphology.[1] The species was first formally described in 2012 by Michael Clyde Hislop and Caroline Puente-Lelièvre from specimens collected north-west of Collie in 2006. The specific epithet (extremus) refers to the "remarkably aberrant morphology" of the species.[2] It is listed as "Priority Two" by the Western Australian Government Department of Biodiversity, Conservation and Attractions, meaning that it is poorly known and from only one or a few locations.[3]