Chromosera cyanophylla is a species of waxcap mushroom in the family Hygrophoraceae, found in old-growth and semi-natural grasslands across temperate Europe. It is particularly notable for producing fruiting bodies with a striking blue-violet or lilac coloration in the gills and stipe, as reflected in its species name, which translates approximately to blue-violet gills. The cap may be pale to ochre and the gills retain vivid blue-violet hues that are distinctive among grassland fungi. Waxcap grasslands are ecologically sensitive habitats dependent on long continuity of traditional pastoral management without artificial fertilizers. The communities of specialist fungi that develop in these habitats — including waxcaps, earthtongues, and pinkgills — take decades to centuries to develop and are destroyed rapidly by any intensification of land management. Chromosera cyanophylla is a species of conservation interest in several European countries and is included in national red lists where its populations have been assessed. The ongoing conversion of traditionally managed meadows and pastures to improved agricultural land represents the principal threat to this and many related waxcap species across Europe.