Keitheatus is a genus of skeletonizing leaf beetles in the family Chrysomelidae. There is one described species in Keitheatus, Keitheatus blakeae. They are found in Texas and Mexico.
A second species, Keitheatus histrio from Baja California in Mexico, was originally included in the genus, but was transferred to Pseudoluperus in 2005 and Amplioluperus in 2022.