Peziza fimeti is a species of ascomycete fungus belonging to the family Pezizaceae.

Found in Europe and North America, the fungus grows on cow dung.

It produces small, light brown, cup-shaped fruit bodies up to 2 cm (0.8 in) in diameter.

The asci (spore-producing cells) are cylindrical (or nearly so), with dimensions of up to 280 μm long and 18 μm in diameter.

The spores are ellipsoid and measure 8 by 16 μm.