Conch (/ˈkɒŋk/ or /ˈkɒntʃ/)[1] is a common name that is applied to a number of different medium to large-sized sea snails or their shells. The term generally applies to large sea snails whose shell has a high spire and a noticeable siphonal canal (in other words, the shell comes to a point at both ends).

True conches are marine gastropod molluscs in the family Strombidae, specifically in the genus Strombus and other closely related genera such as Eustrombus.

Many species also are often called "conch", but are not in the family Strombidae, including Melongena species (family Melongenidae), and the horse conch Pleuroploca gigantea (family Fasciolariidae). They also include the sacred chank or more correctly shankha shell (Turbinella pyrum) and other Turbinella species in the family Turbinellidae.