Galbinothrix caesiopruinosa is described from Japan and Korea. The new genus and species is placed in Chrysotrichaceae by its ascoma morphology and by a phylogenetic analysis of mtSSU and nLSU sequence data using Bayesian and maximum likelihood inference. The monotypic genus Galbinothrix is superficially similar to Chrysothrix caesia in having dark brown ascomata covered by a thin bluish grey pruina, reddish brown ascomatal pigment in the epithecium and proper exciple, the greyish green to yellowish olive thallus, and usnic acid as the main secondary thallus compound. It differs from this species and all other Chrysotrichaceae by its large, oblong, thick-walled ascospores with a distinct epispore, the narrowly clavate to almost tubular asci, and the never clearly granular to leprose thallus.