Fissurellidae, common name the keyhole limpets and slit limpets, is a taxonomic family of limpet-like sea snails, marine gastropod molluscs in the clade Vetigastropoda. Their common name derives from the small hole in the apex of their cone-like shells. Although superficially resembling "true" limpets, they are in fact not closely related to them.
The distribution of fissurellids is worldwide, from cold waters to tropical waters.
Fissurellids live in habitats on and under rocks in the lower intertidal zones to deeper waters.