Pertusaria krabiensis is a rare species of corticolous (bark-dwelling), crustose lichen in the family Pertusariaceae. Found in peninsular Thailand, it was formally described as a new species in 2005 by Sureeporn Jariangprasert. The type specimen was collected from near the Wat Thamp Suea Temple in Krabi; the species is known only from the type. The species epithet combines the name of the type locality with the Latin suffix -ensis ("place of origin"). The main distinguishing characteristics of Pertusaria krabiensis are its ascospores (which number 8 per ascus), and the presence of homologues of the lichen product 2-O-methylperlatolic acid.