The Gelechiidae are a family of moths commonly referred to as twirler moths or gelechiid moths. They are the namesake family of the huge and little-studied superfamily Gelechioidea, and the family's taxonomy has been subject to considerable dispute. These are generally very small moths with narrow, fringed wings. The larvae of most species feed internally on various parts of their host plants, sometimes causing galls. Douglas-fir (Pseudotsuga) is a host plant common to many species of the family, particularly of the genus Chionodes, which as a result is more diverse in North America than usual for Gelechioidea.

Gelechioidea is the superfamily of moths that contains the case-bearers, twirler moths, and relatives, also simply called curved-horn moths or gelechioid moths. It is a large and poorly understood '"micromoth" superfamily, constituting one of the basal lineages of the Ditrysia.