Buccinum undatum, the common whelk or the waved buccinum, is a large, edible marine gastropod in the family Buccinidae, the "true whelks".

The waved or common whelk (Buccinum undatum) is a cold-water subtidal marine gastropod, distributed through the North Atlantic and adjoining seas. Throughout its distribution, it is commercially important and has been harvested in Europe and Canada for both bait and human consumption for decades [ 1, 2, 3, 4 ].

Snails in this genus are commonly called whelks, a name shared with several related and unrelated species. The common whelk Buccinum undatum is the most common representative of the genus in the northern Atlantic Ocean.