Isonychus pulchellus is a species of beetle of the family Scarabaeidae. It is found in Peru.
Adults reach a length of about 6 mm. They are yellowish-red and densely covered with scales above and below. The frons has yellow and brown scales and the antennae are yellowish-brown, with a black club. The pronotum is covered with yellowish-white scales, a large central blackish-brown spot bears scattered light scales. On the elytra, the scales are blackish-brown, and the elytra are also speckled with numerous brown and white scales. On the underside, the scales are white, with individual yellowish spots along the sides.