Polyphylla simoni is a species of beetle of the family Scarabaeidae. It is found in Thailand and Vietnam.
Adults reach a length of about 20âÂÂ23 mm. They have an elongate, moderately convex body. The surface colour is chestnut brown, with the pronotum very slightly darker. The dorsal surface of the head, pronotum and scutellum is covered with whitish to pale ochrous scales, and the elytra with whitish scales.
The species is named in honor of à  imon, son of the first author.