A new species, Collybiopsis pakistanica, from Margalla Hills National Park, Pakistan, is described based on micro-morphological and molecular phylogenetic analyses. This species is characterized by its milky white pileus, yellowish orange or light yellow to orange at central disc and margins, lacrymoid basidiospores, cheilocystidia with median construction, and broadly utriform and clavate to narrowly utriform pleurocystidia and epithelioid hymeniderm pileipellis. Its placement as a new taxon of Collybiopsis is confirmed by phylogenetic analyses of ITS and nrLSU sequences. Two new combinations, Collybiopsis ugandensis and Collybiopsis pleurocystidiata are also proposed as these species are transferred from Gymnopus.