Gloioxanthomyces vitellinus is a species of agaric (gilled mushroom) in the family Hygrophoraceae.

[1] Threats to its habitat have resulted in the glistening waxcap being assessed as globally "endangered" on the IUCN Red List of Threatened Species.

The species was first described by Swedish mycologist Elias Magnus Fries in 1863 as Hygrophorus vitellinus.

[1] Like many other European waxcaps, it occurs in old, agriculturally unimproved, short-sward grassland (pastures and lawns).

Gloioxanthomyces vitellinus is typical of waxcap grasslands, a declining habitat due to changing agricultural practices.