Parmotrema aptrootii is a species of corticolous lichen in the family Parmeliaceae. Found in South America, it was described as new to science in 1992. The holotype specimen was collected in the Cuyuni-Mazaruni region of Guyana, where it was found growing on a Mahogany tree on the bank of the Kamarang River. It has a pale yellowish to greenish-grey thallus measuring up to about 10abbr=onNaNabbr=on. The specific epithet honours Dutch lichenologist André Aptroot. The lichen has also been recorded from Acre, Brazil, where it is commonly found on dead branches in dense shrubby campinas.