We provide a synopsis of the Sumatran species in the scarab beetle genus Peltonotus Burmeister (Scarabaeidae: Dynastinae: Cyclocephalini), describe a new species of Peltonotus from Sumatra, and describe the male of P. cybele Jameson & Wada from Sumatra (previously known only by the female holotype). To enable identifi cation, we include a key to the fi ve Sumatran species of Peltonotus, comparative images and diagnoses for all species, and temporal and geographical distributions.