Coleophora millefolii is a moth of the Coleophoridae family. It is found in most of Europe, except Great Britain, Ireland and the Iberian Peninsula. The wingspan is 11–12 mm. Adults are on wing from the end of June to August. The larvae feed on Achillea millefolium. They create a compact, sausage-shaped, hairy case, built out of numerous leaf fragments. The mouth angle is about 45°. Larvae can be found from autumn to June.