The trefoil thick-horned tinea or large clover case-bearer (Coleophora trifolii) is a moth of the Coleophoridae family. It is found in Europe, North Africa, Asia Minor, Afghanistan and North America. The wingspan is 15–20 mm. Adults are on wing from June to July. They are active during the day. The larvae feed on the seeds of Melilotus species (including Melilotus officinalis and Melilotus altissima).