Lieinix nemesis, the frosted mimic-white, nemesis mimic white or falcate dismorphia, is a butterfly in the family Pieridae. It is found from Mexico to Peru. The habitat consists of mid-elevation cloudforests.
The wingspan is . Adults are sexually dimorphic.
The larvae probably feed on Inga species, including Inga mortoniana and Inga densiflora.
The following subspecies are recognised: