The Agaricaceae are a family of basidiomycete fungi and include the genus Agaricus, as well as basidiomycetes previously classified in the families Tulostomataceae, Lepiotaceae, and Lycoperdaceae.

Agaricus is a genus of mushroom-forming fungi containing both edible and poisonous species, with over 400 members worldwide and possibly again as many disputed or newly-discovered species. The genus includes the common ("button") mushroom and the field mushroom, the dominant cultivated mushrooms of the West.