Diplognatha gagates is a species of beetle belonging to the family Scarabaeidae, subfamily Cetoniinae.
Diplognatha gagates can reach a length of about . The thorax is very . The surface is shining black or reddish. Larvae feed on bird droppings. Young adults are usually reddish brown and feed on flowers, fruits and sap.
This species is widespread in almost all African countries south of the Sahara.