Fissurella mutabilis, common name Cape keyhole limpet, is a species of sea snail, specifically in the family Fissurellidae (keyhole limpets).
The size of the shell reaches 18 mm.
F. mutabilis is commonly found off the coast in Madagascar, Namibia, and South Africa. It is confirmed to be present near ÃÂle Amsterdam and ÃÂle St. Paul; samples have also been found near the Kerguelen Islands and on the high seas in the South Atlantic.