The Leon Springs pupfish (Cyprinodon bovinus) is a species of fish in the family Cyprinodontidae. It is endemic to Texas in the United States, where it is limited to Pecos County, Texas. It is a federally listed endangered species.
This fish was first discovered in 1851 at Leon Springs, near Fort Stockton, Texas. Leon Springs was impounded, poisoned, stocked with game fish, and drained, and the fish was considered extinct by 1938. In the 1960s it was rediscovered at Diamond Y Spring a few miles away. It is also found in the Diamond Y Draw, a tributary of the Pecos River.