Montane guinea pig in the context of "Cavia"

The guinea pig or domestic guinea pig (Cavia porcellus), also known as the cavy or domestic cavy (/ˈkeɪvi/ KAY-vee), is a species of rodent belonging to the genus Cavia, family Caviidae. Breeders tend to use the name "cavy" for the animal, but "guinea pig" is more commonly used in scientific and laboratory contexts. Despite their name, guinea pigs are not native to Guinea, nor are they closely related to pigs. Instead, they originated in the Andes region of South America, where wild guinea pigs can still be found today. Studies based on biochemistry and DNA hybridization suggest they are domesticated animals that do not exist naturally in the wild, but are descendants of a closely related cavy species such as C. tschudii. Originally, they were domesticated as livestock (source of meat) in the Andean region and are still consumed in some parts of the world.

In Western society, the guinea pig has enjoyed widespread popularity as a pet since its introduction to Europe and North America by European traders in the 16th century. Their docile nature, friendly responsiveness to handling and feeding, and the relative ease of caring for them have continued to make guinea pigs a popular choice of household pets. Consequently, organizations devoted to the competitive breeding of guinea pigs have been formed worldwide. Through artificial selection, many specialized breeds with varying coat colors and textures have been selected by breeders.