A bucking horse is any breed of horse, male or female, with a propensity to buck. They have been, and still are, referred to by various names, including bronco, broncho, and roughstock.

Bucking is a movement performed by an animal in which it lowers its head and raises its hindquarters into the air while kicking out with the hind legs. It is most commonly seen in herbivores such as equines, cattle, deer, goats, and sheep. Most research on this behavior has been directed towards horses and cattle.