Acallosuchus (meaning "ugly crocodile" in Greek) is an extinct genus of reptile from the Triassic Chinle Formation of the southwestern United States. Although it was discovered in 1923, Acallosuchus was not described until 1989, when the type species A. rectori was named. The taxonomy classification of Acallosuchus is uncertain. Although it is known to be a neodiapsid reptile, it has not been assigned with confidence to any particular group of neodiapsids.