A new species of cyprinid, Notropis calabazas, is described from the Río Calabazas, a small tributary of the Río Verde in the Río Pánuco basin in San Luis Potosí state, central México. It belongs to the Notropis calientis complex, which is defined primarily on the occurrence of reduced and interrupted cephalic and lateralis sensory canals. Notropis calabazas is unique in having 17 or more gill rakers on the second gill arch versus 16 or fewer. Notropis calabazas can also be distinguished from the other three members of the complex by its relatively high numbers of gill rakers on the first arch, total lateral line scales, pored lateral line scales, body circumferential scale rows and caudal peduncle circumferential scale rows, and its relatively low numbers of supraorbital and infraorbital cephalic sensory pores. Notropis calabazas is uncommon within its limited range and warrants official designation as a protected species.