Plectris cylindriformis is a species of beetle of the family Scarabaeidae. It is found in Venezuela.
Adults reach a length of about 10 mm. They are dark brown, with the clypeus glabrous and the upper surface sparsely but fairly regularly covered with somewhat unequal, light-coloured setae. On the pronotum, the setae are a little longer and more erect. The pygidium is moderately densely covered with erect setae and the scutellum is pubescent like the elytra.