During a floristic survey of Croton in montane areas of the Cerrado biome of Central Brazil, a new species, Croton gracilirameus, was discovered and is herein described, illustrated, and compared to its putative closest relatives, C. agoensis and C. catariae. The new species most likely belongs to Croton section Geiseleria due to its stellate trichomes, leaves with glands at the apex of the petiole and margins, thyrses with a brief interruption between the pistillate and staminate flowers, and pistillate flowers with valvate sepals. A key to Croton gracilirameus and allied species, a synonymization of C. chaetocalyx under C. catariae, and new occurrence records of C. arirambae are also provided.