The modest whorltail iguana (Stenocercus modestus) is a species of lizard of the family Tropiduridae.
It is endemic to west-central Peru. It was first described by Johann Jakob von Tschudi in 1845.
The species is thought to have a highly fragmented and decreasing population, and is therefore rated as endangered by the IUCN. It lives in the coastal desert and has a diet consisting of arthropods.