The Jetmore Chalk Member of the Greenhorn Limestone is a Late Cretaceous rock unit deposited under the Western Interior Seaway in North America. We here report an assemblage of vertebrate fossils collected through surface collecting and bulk sampling at a new Jetmore Chalk locality in Republic County, Kansas, U.S.A. Taxonomically, it consists of diverse carnivorous fish taxa (e.g., Ptychodus, Cretoxyrhina, Squalicorax, Pachyrhizodus, and Plethodidae), indicating that the marine paleoecology during the deposition of the Jetmore Chalk was quite complex. The fossil assemblage also includes the first record of the aquatic lizard, Coniasaurus cf. C. crassidens, from the Jetmore Chalk, as well as the first record of a ‘billfish’-type bony fish, Cylindracanthus sp., from Kansas that also represents the oldest fossil record for the genus. Whereas the overall taxonomic composition of known fossil vertebrates from the Jetmore Chalk is consistent with typical Cenomanian-Santonian vertebrate assemblages of the Western Interior Seaway, this study demonstrates the presence of local differences in the relative abundance of fossils across different fish taxa between a known Jetmore Chalk locality and the new Jetmore Chalk locality described in this study.