The Goldfish, Carassius auratus, was one of the earliest fish to be domesticated, and is still one of the most commonly kept aquarium fish and water garden fish. A relatively small member of the carp family, the goldfish is a domesticated version of a dark-gray/brown carp native to East Asia. It was first domesticated in China and introduced to Europe in the late 17th century.

Goldfish can grow to a maximum length of 23 inches (159 cm) and a maximum weight of 9.9 pounds (4.5 kg), although this is rare; few goldfish reach even half this size. The oldest recorded goldfish lived to 49 years,but most household goldfish generally live only six to eight years, due to being kept in bowls. The collective noun for a group of goldfish is a "troubling".