Bonnerichthys is an extinct, prehistoric pachycormiform in the family Pachycormidae from the Late Cretaceous of North America. It only has one species, B. gladius.
Finds were made in the Smoky Hill Member of the Niobrara Formation of Kansas (Late Coniacian-Early Campanian), and additional material was later reported from the Pierre Shale, Mooreville Chalk, Demopolis Chalk, Wenonah Formation, and Moreno Formation.
It was probably related to Rhinconichthys and Leedsichthys.