Hoplia plebeja is a species of beetle of the family Scarabaeidae. It is found in China (Yunnan) and Laos.
Adults reach a length of about . They are reddish-brown, with the top of the head black. The upper surface is covered with brown, yellowish-brown, and blackish-brown scales and there are two pairs of dark spots on the disc of the elytra, as well as a pair of longitudinal dark stripes on the disc of the pronotum. The pygidium, underside and legs are paler and covered with greyish-brown, yellowish-brown, and golden-yellow scales. All hairs and setae are light.