The Old World porcupines, or Hystricidae, are large terrestrial rodents, distinguished by the spiny covering from which they take their name. They range over the south of Europe and the Levant, most of Africa, India, and Southeast Asia as far east as Flores. Although both the Old World and New World porcupine families belong to the infraorder Hystricognathi of the vast order Rodentia, they are quite different and are not particularly closely related.

In a zoological context, spines are hard, needle-like anatomical structures found in both vertebrate and invertebrate species. The spines of most spiny mammals are modified hairs, with a spongy center covered in a thick, hard layer of keratin and a sharp, sometimes barbed tip.