Tetraodontidae is a family of primarily marine and estuarine fish. The family includes many familiar species which are variously called puffers, balloonfish, blowfish, bubblefish, globefish, swellfish, toadfish, and toadies. They are morphologically similar to the closely related porcupinefish, which have large conspicuous spines (unlike the small, almost sandpaper-like spines of Tetraodontidae). The scientific name, Tetraodontidae, refers to the four large teeth, fused into an upper and lower plate, which are used for crushing the shells of crustaceans and mollusks, and red worms, their natural prey.

Puffer fish are the second most poisonous vertebrate in the world, the first being a Golden Poison Frog. The skin and certain internal organs of many tetraodontidae are highly toxic to humans, but nevertheless the meat of some species is considered a delicacy in both Japan (as fugu) and Korea (as bok). If one is caught while fishing, it is recommended that thick gloves be worn to avoid poisoning and getting bitten when removing the hook.

The tetraodontidae contains at least 121 species of puffers in 19 genera. They are most diverse in the tropics and relatively uncommon in the temperate zone and completely absent from cold waters. They are typically small to medium in size, although a few species can reach lengths of 100 centimetres (39 in).