Pluteus phaeocyanopus is an agaric fungus in the family Pluteaceae.

Described as a new species in 2010, it has only been collected from California, where it grows singularly or in groups on the decaying wood of oak.

The fruit body has a smooth brown cap measuring 2–4 cm (0.8–1.6 in) in diameter.

[1] The species was originally collected from San Francisco (California) in 1966 by American mycologist Harry D. Thiers and assigned to Pluteus cyanopus.

However, a reexamination of the type material revealed that it has microscopic characters distinct from that species, which prompted authors Andrew Minnis and Walter Sundberg to describe the California collection as a new species.