Prawns are edible, shrimp-like crustaceans. In Britain the name is applied to any large shrimp, usually Leander serratus, but in the United States the word "prawn" usually indicates a fresh-water, rather than salt-water, shrimp.

Specialists would only apply the term prawn to members of the Dendrobranchiata, such as Penaeus and related genera.

The word in Middle English is prayne or prane, and no cognate forms are found in any other languages. It has been often connected to the Latin perna, a ham-shaped shellfish, but this is due to an old scholarly error that connected perna and parnocchie with prawne-fishes or shrimps. In fact, the Old Italian perna and pernocchia meant a shellfish that yielded nacre, or mother-of-pearl.