Calsoyasuchus (meaning "[Dr. Kyril] Calsoyas' crocodile") is a genus of crocodylomorph that lived in the Early Jurassic. Its fossilized remains were found in the Sinemurian-Pliensbachian-age Kayenta Formation on Navajo Nation land in Coconino County, Arizona, United States. Formally described as C. valliceps, it is known from a single incomplete skull which is unusually derived for such an early crocodile relative. This genus was described in 2002 by and colleagues; the specific name means "valley head" and refers to a deep groove along the midline of the nasal bones and frontal bones. It has often been intrepretted as the earliest diverging member of Goniopholididae, but other studies have recovered it in various other positions.