Psilocybe cubensis, commonly known as the magic mushroom, shroom, golden halo, cube, or gold cap, is a species of psilocybin mushroom of moderate potency whose principal active compounds are psilocybin and psilocin. It belongs to the fungus family Hymenogastraceae and was previously known as Stropharia cubensis. It is the best-known psilocybin mushroom due to its wide distribution and ease of cultivation. This mushroom being optimal for home cultivation specifically, as was suggested in the 1970s, is primarily what led to P. cubensis being the psilocybin mushroom species most common on the black market as a street drug.

Psilocybin mushrooms, commonly known as magic mushrooms or shrooms, are a polyphyletic informal group of fungi that contain psilocybin, which turns into psilocin upon ingestion. Biological genera containing psilocybin mushrooms include Psilocybe, Panaeolus, Inocybe, Pluteus, Gymnopilus, and Pholiotina.