Elachista is a genus of gelechioid moths described by Georg Friedrich Treitschke in 1833. It is the type genus of the grass-miner moth family (Elachistidae). This family is sometimes (in particular in older sources) circumscribed very loosely, including for example the Agonoxenidae and Ethmiidae which seem to be quite distinct among the Gelechioidea, as well as other lineages which are widely held to be closer to Oecophora than to Elachista and are thus placed in the concealer moth family Oecophoridae here.