Athyrium (lady-fern) is a genus of about 180 species of terrestrial ferns, with a cosmopolitan distribution.

It is placed in the family Athyriaceae, in the order Polypodiales.

[1][2] Its genus name is from Greek a- ('without') and Latinized Greek thyreos ('shield'), describing its inconspicuous indusium (sorus' covering).

[3] The common name "lady fern" refers in particular to the common lady fern, Athyrium filix-femina.

[4] Athyrium species are used as food plants by the larvae of some Lepidoptera species including the small angle shades and Sthenopis auratus.