Hylocelis diabloensis is a species of flatworm belonging to the family Cryptocelidae.

H. diabloensis is elliptical in shape, with an undulating margin.

The color ranges from grey to pinkish, with a mid-dorsal longitudinal stripe that is reddish-brown.

[2] The species is named after Punta del Diablo, where the type specimens were collected.

[2] The species is known to be found on shoreline rocks in Uruguay, around Santa Teresa National Park.