Porcupinefishes or balloonfishes, are any of the various species of the genus Diodon, the type genus of Diodontidae.

Fish of the genus Diodon have: They differ from the swelltoads and burrfishes (genera Cyclichthys and Chilomycterus, respectively), which, in contrast, have fixed, rigid spines.

There are currently five recognized extant species in this genus:[4] Fossils of porcupinefishes are known from Tertiary-aged marine strata.

Fossil species include:

This Tetraodontiformes article is a stub.