Pleurotus is a genus of gilled mushrooms which includes one of the most widely eaten mushrooms, P. ostreatus. Species of Pleurotus may be called oyster, abalone, or tree mushrooms, and are some of the most commonly cultivated edible mushrooms in the world. Pleurotus fungi have been used in mycoremediation of pollutants such as petroleum and polycyclic aromatic hydrocarbons.

The Oyster mushroom is a common mushroom prized for its edibility and lack of confusing look-alikes.

The oyster is one of the more commonly sought wild mushrooms, though it can also be cultivated on straw and other media. The margin can be smooth with a slight wave. The flesh of the most common variety is white and can be thin or thick. A range of different colors can be found in the wild and can be cultivated. Yellow, pink, blue, and gray. Gills are decurrent (descend down the stem) and attached and white to light yellow. The stem is short, often horizontal and emerging from wood. The spores form a white to lilac-gray print on dark media. The mycelia is white and grows rapidly.

This is a wide-spread mushroom in much of North America and other continents. Grows on dead wood year round. All strains need moist conditions to fruit, although different strains fruit in different temperature ranges.

The caps may be laterally attached (with no stem). If there is a stem, it is normally eccentric and the gills are decurrent along it. The term pleurotoid is used for mushrooms having this general shape.

The spores are smooth and elongated (described as "cylindrical"). Where hyphae meet, they are joined by clamp connections. Pleurotus is not considered to be a bracket fungus, and most of the species are monomitic (with a soft consistency). However, remarkably, Pleurotus dryinus can sometimes be dimitic, meaning that it has additional skeletal hyphae, which give it a tougher consistency like bracket fungi.