Cortinarius glaucopus, commonly known as the blue-foot webcap, is a basidiomycete mushroom of the genus Cortinarius native to Europe and North America. The species was first described as Agaricus glaucopus by Jacob Christian Schäffer in 1774. It was given its current name by Elias Magnus Fries in 1838. Within the genus Cortinarius, it is classified in the subgenus Phlegmacium and section Glaucopodes. A 2014 genetic study confirmed it was synonymous with C. glaucopoides and that Cortinarius subrubrovelatus was a distinct species. Common names in other languages include Schwachknolliger Klumpfuss (German), Cortinaire à pied glauque (French) and Szálaskalapú pókhálósgomba (Hungarian).