Gastroserica namthana is a species of beetle of the family Scarabaeidae. It is found in Laos.
Adults reach a length of about 5.8âÂÂ6.8 mm. They have a yellowish brown, egg-shaped, oval body, with two darker symmetrical stains on the pronotum. The pronotum also has lighter margins and three lighter stripes. The elytra have dark stripes. The dorsal surface has a coppery-green sheen and is nearly glabrous, except for the cilia along the margins of the pronotum and elytra and a few long setae on the elytra.