Gastroserica muongphangensis is a species of beetle of the family Scarabaeidae. It is found in Vietnam.
Adults reach a length of about 8.5 mm. They have a dark brown, oval body. The dorsal surface is dull and has robust, moderately dense, erect setae, mixed with dense and very short ones.
The species is named after the type locality, Muong Phang District, Dien Bien Province.