Diabloceratops lived on the paleo continent of Laramidia 80 million years ago when the Cretaceous Interior Seaway was at it's greatest extent, cutting off the region that is now Southern Utah from the rest of the continent. The Wahweap Formation where this specimen was found was made up of lakes, floodplains and east-flowing rivers on the narrow swath of land between the ancient mountains and the interior sea. The name is taken from the Spanish word meaning "devil" and refers to the prominent horns protruding from the frill of this animal.