Athyrium filix-femina, the lady fern or common lady-fern, is a large, feathery species of fern native throughout most of the temperate Northern Hemisphere, where it is often abundant (one of the more common ferns) in damp, shady woodland environments and is often grown for decoration.

Its common names "lady fern" and "female fern" refer to how its reproductive structures (sori) are concealed in an inconspicuous – deemed "female" – manner on the frond. Alternatively, it is said to be feminine because of its elegant and graceful appearance.