Dichomeris caustonota is a moth in the Gelechiidae family. It was described by Meyrick in 1914. It is found in Guyana. The wingspan is about 13 mm. The forewings are yellow-ochreous with the costal edge blackish towards the base and a moderate dark fuscous streak along the dorsum from the base to the tornus, somewhat dilated before the middle. There is a triangular dark fuscous patch extending on the costa from two-fifths to four-fifths, and reaching half across the wing, edged with silvery-whitish. There is a roundish blotch of dark fuscous suffusion before the termen beneath the apex and there are some black terminal dots. The hindwings are dark fuscous.