Cyprinodon rubrofluviatilis, known as the Red River pupfish, is a species of pupfish from the United States. It is found only in the Red River of the South and Brazos River drainages of Texas and Oklahoma.
It grows to a total length of and feeds on midge larvae and other insects. It was first described by Henry Weed Fowler in 1916, as a subspecies of the species Cyprinodon bovinus; the specific epithet ' refers to the Red River.