The goldfish, Carassius auratus, is a popular ornamental aquarium and pond fish from the family Cyprinidae. It was one of the earliest domesticated species of fish, originally being domesticated in China, and have become a favourite among aquarium owners in the modern day.

There is some debate as to the origns of goldfish - with both C. carassius and C. gibelio being marked as possible ancestors.

Due to selective breeding, many colour forms and unique body shapes have come about in the aquarium hobby, although the so-called 'common goldfish' - that being the variety with a shape most similar to wild forms - are still a popular choice for aquarium and pond keepers.