Cortinarius is one of the most species-rich, conspicuous and widespread genera of basidiomycete ectomycorrhizal fungi. While knowledge of the morphogenetic diversity of Cortinarius in central and northern Europe is rather extensive, less is known about the genus in other regions, such as the Iberian Peninsula. The present study assesses the taxonomical status of an unknown Cortinarius species from the Cadí-Moixeró Natural Park (north-eastern Iberian Peninsula), using morphological, phylogenetic and ecological data. As a result, C. uxorum is presented as new species in C. subg. Telamonia sect. Firmiores. It is phenotypically recognized by its medium to large-sized, stout basidiomata with persistent and copious whitish to silvery-white veil remnants on the pileus margin, and the ring-like stripe on the upper stipe. The restricted distribution of this species to a Natural Park highlights the need to consider fungi as a pivotal component of biodiversity in conservation policies.