Diodora rueppellii, common name the Rüppell's keyhole limpet, is a species of sea snail, a marine gastropod mollusc in the family Fissurellidae, the keyhole limpets.

Diodora ruppellii has a shell with a whitish exterior marked with a radial pattern of dark blotches and a white interior surface marked with a faint pattern similar to the exterior.

[2] Diodora ruppellii has an Indo-Pacific distribution occurring in the Red Sea and along the east African coasts as far south as KwaZulu-Natal and east through the Indian Ocean and Pacific Ocean to Hawaii.

[2] Species in the genus Diodora feed on sponges from the undersides of rocks and boulders.

Diodora ruppellii is normally found in the intertidal zone on rocky shores but has been dredged up from gravel substrates.