A tiny feline mandibular corpus fragment from the late Middle Pleistocene fossil hominin locality of Hualongdong is reported here as a new species Prionailurus kurteni. This species represents the smallest known fossil member of the family Felidae to date, comparable in size to two of the smallest modern cats, P. rubiginosus and Felis nigripes. It is unique in having a small p4 mesial accessory cuspid, very weak p4 distal cingulid, relatively deep mandibular corpus under m1, and a distally located anterior border of the masseteric fossa. A notable synapomorphy observed in the lineage including Prionailurus, Felis and Otocolobus, is the mesially inclined m1. The identification of P. kurteni suggests a potentially high diversity of Prionailurus during the prehistorical time, underscoring the significance of revisiting the taxonomy of small Felidae to gain a better understanding of the evolution and diversification of this family.