Eudonia laetella is a species of moth in the Crambidae family. It is found in Fennoscandia, the Baltic region, Belarus, Russia, Poland, the Czech Republic, Slovakia, Hungary, Romania, Bosnia and Herzegovina, the Republic of Macedonia, Greece, Slovenia, Austria, Switzerland, Italy, Germany and Belgium. The wingspan is 16–20 mm. Adults are on wing in January and from June to August. The larvae feed on moss on trunks.