Chamaecrista tocantinensis, a new species of Chamaecrista sect. Absus subsect. Absus ser. Paniculatae endemic to the Jalapão region in the state of Tocantins, Northern Brazil, is herein described and illustrated. The systematic position, conservation status, flowering and fruiting period, geographical distribution, and morphological relationships of this novel species with C. claussenii var. megacycla, C. lundii, and C. orbiculata var. orbiculata are discussed. A key to all taxa of Chamaecrista hitherto known from the state of Tocantins, including ten new state records, is also provided.