Harness racing is the type of horse racing in which horses pull a lightweight two-wheeled cart called a sulky. A driver sits in the sulky while the horse races at a prescribed gait, usually a trot or a pace, rather than galloping.
The sport’s defining feature is the harness and the cart, not a particular breed alone. Modern harness racing is strongly associated with the Standardbred, a breed developed for speed, stamina, and reliable performance at the trot or pace. Races may be contested over different distances, with competitors required to maintain the specified gait; breaking into a gallop can lead to a penalty or disqualification.
Harness racing developed from practical horse-and-cart transportation and became organized as a sport in the 18th and 19th centuries. The sulky gradually evolved into a lighter, faster racing vehicle, while standardized rules made competition more consistent.
A common mix-up is confusing harness racing with thoroughbred racing. Thoroughbreds generally race under saddle at a gallop, whereas harness-racing horses pull the driver behind them.