Hypsiboas rhythmicus is a species of frog in the Hylidae family. It is endemic to Venezuela and only known from its type locality, Cerro Jaua in Bolívar State. It occurs along streams on the slopes of the tepui. It is a nocturnal species found on branches of vegetation 0.3–1 m (1–3 ft) above the ground. The tepui is within the Jaua-Sarisariñama National Park, and no major threats to this species have been identified.