Crocanthes gelastis is a moth in the Lecithoceridae family. It was described by Meyrick in 1918. It is found in New Guinea. The wingspan is about 17 mm. The forewings are dark purple-fuscous with an irregular transverse deep yellow spot crossing the end of the cell, not reaching the costa or dorsum. The hindwings are dark fuscous with a rather broad rather irregular deep yellow fascia from somewhat beyond the middle of the costa to the termen above the tornus.