The Pfeifer Shale Member of the Greenhorn Limestone is a Late Cretaceous (early Turonian) rock unit deposited in the Western Interior Seaway in North America. Approximately 50 isolated skeletal and dental elements of fossil fishes were recently recovered from the lower part of the Pfeifer Shale at a locality in south-central Republic County, Kansas, U.S.A. They include a minimum of three chondrichthyan taxa and six osteichthyan taxa, including Ptychodus cf. P. whipplei, Cretoxyrhina mantelli, Squalicorax cf. S. falcatus, Caturidae indet., Actinopterygii (non-teleostean?) indet., Pachyrhizodus minimus, Enchodus shumardi, and at least two additional teleost species. Even though the sample size is small, the present study provides a glimpse into the rich diversity of the fish fauna that encompasses a wide range of trophic regimes, including small bony fishes with small sharp teeth suited for catching smaller fishes and soft-bodied invertebrates, as well as durophagous, predatory, and scavenging sharks.