Coleophora tamesis is a moth of the Coleophoridae family. It is found in most of Europe and is also known from the eastern part of the Palearctic ecozone and the Near East. It is also found in China. The wingspan is 11–14 mm. Adults are on wing from mid-June to August. The larvae feed on the generative organs of Juncus articulatus and Juncus compactus. They form a case made from silk and the remains of the seed capsule. It is 6–7 mm in length. The larvae overwinter. Pupation takes place in May and June.