Phryxus is a monotypic moth genus in the family Sphingidae first described by Jacob Hübner in 1819.

Its only species, Phryxus caicus, was described by Pieter Cramer in 1777.

It is found in the Neotropics, although it has been recorded from southern Florida and South Carolina.

In the tropics, larvae have been recorded on Apocynaceae species.

In Florida, it has been recorded on Rhabdadenia bilfora.