Cardioglossa trifasciata is a species of frog in the family Arthroleptidae. It is endemic to western Cameroon and only known from the southern slopes of Mount Manengouba. Common name Nsoung long-fingered frog has been coined for it.
Males measure 24–31 mm (0.9–1.2 in) and females 30–41 mm (1.2–1.6 in) in snout–vent length. Males have extremely long third fingers and spines in the fingers and in the groin; females lack these characteristics. Dorsal markings typical for the genus Cardioglossa are present, whereas the white line running under the tympanum is absent.