Mycena crocea, commonly known as the walnut mycena, is a species of mushroom in the Mycenaceae family. The small, inconsequentially edible mushroom has a bright yellow, conical to broadly convex cap up to 15 mm (0.6 in) in diameter. The stem is tough and thin, up to 20 mm (0.8 in) tall, bright yellow at the top becoming progressively orange towards the base. The gills are adnate, subdistant, and yellowish, becoming lighter in age; and the spore print is white. This mushroom is saprobic and found exclusively on hickory nuts and walnuts in eastern North America. The specific epithet crocea refers to the orange color. The mushroom is commonly known as the "walnut mycena" and was previously and commonly misidentified as Mycena luteopallens.