Untomia formularis is a moth of the Gelechiidae family. It was described by Meyrick in 1929. It is found in Brazil (Amazonas) and Colombia. The wingspan is about 9 mm. The forewings are dark fuscous with an oblique white strigula from the costa at three-fourths, with beyond this a blackish streak along the costa to the apex. There is a whitish or brown white-edged elongate apical mark, and a slender irregular whitish terminal streak touching this but leaving a blackish dot beneath apex, and a whitish tornal dot. The hindwings are grey.