Cortinarius nauseosouraceus is a species of mushroom in the family Cortinariaceae.
The cap of Cortinarius nauseosouraceus is brown. It starts out conical or round and becomes convex, flat, or umbonate. It is about 3âÂÂ8.5 centimeters in diameter. The stipe is about 6-11 centimeters long and 0.4-0.9 centimeters wide at the top, and is slightly wider at the base. At the base of the stipe, there is yellowish mycelium. The gills are emarginate and start out yellowish brown, becoming browner in age. The spore print is rusty brown.
Cortinarius nauseosouraceus is found coniferous forests. It is often found in the Cascades and Olympic Mountains, where it fruits during the autumn season.