Tetraserica hilaris is a species of beetle of the family Scarabaeidae. It is found in India (Arunachal Pradesh).
Adults reach a length of about 7.3 mm. They have a reddish brown, oval body. The antennae are yellowish. The dorsal surface is mostly dull and very sparsely setose.
The species name is derived from Latin hilaris (meaning bright or cheerful).