Perigonia ilus is a moth of the family Sphingidae first described by Jean Baptiste Boisduval in 1870.

It is known from Mexico, Honduras, Costa Rica, Belize, Guatemala, El Salvador, Nicaragua, Panama, Colombia, Venezuela, Ecuador, Peru, Bolivia, Argentina, Paraguay, Brazil and Uruguay.

Adults are on wing year round.

The larvae have been recorded feeding on Calycophyllum candidissimum, Guettarda macrosperma and Ilex paraguariensis.

They are green with a yellow tail horn and a dark blue stripe down the back.