Marion Charles Bonner (1911–1992), based for most of his life in Leoti, Kansas, was an American field paleontologist who discovered and collected hundreds of fossils, primarily from the Niobrara Cretaceous Smoky Hill chalk outcroppings in Logan, Scott, and Gove counties of western Kansas. Largely self-taught, he frequently collaborated with museum paleontologists, including George F. Sternberg, at Fort Hays State University in Hays, Kansas, and Shelton P. Applegate, at the Los Angeles County Museum of Natural History.