Tetraserica elargata is a species of beetle of the family Scarabaeidae. It is found in Laos.
Adults reach a length of about 10.4 mm. The dorsal surface is dark brown and glabrous, the pronotum with a weak greenish shine. The ventral surface and the legs are reddish brown and the antennae are yellow.
The species name is derived from Latin elargatus (meaning widened) and refers to its apically widened left paramere.