Saddle seat is a style of horse riding within the category of English riding that is designed to show off the high action of certain horse breeds. The style developed into its modern form in the United States, and is also seen in Canada and South Africa. To a much lesser extent, it is ridden with American horse breeds in Europe and Australia.

The goal of the saddle seat riding style is to show off the horse's extravagant gaits, particularly the trot. It is not to be confused with the various hunt seat disciplines.

Saddle seat riding began as a distinct style within the broader group of English riding disciplines developed in the United States. The first source was the Plantation tradition of the American South, where smooth-moving, high-stepping horses were used by plantation owners and overseers to travel across the fields. The horses had to be smooth riding and comfortable enough for hours of riding while overseeing the plantation, but the owners also preferred an impressive, high-stepping horse for riding in town. A second influence was European: a flatter English show saddle was developed from the tradition of riders who would often show off their flashiest, highest-stepping horses by riding them in city parks on Sundays. Hence, the term "park horse" is still used today to describe competitions in which the action of the horse is of paramount importance. In the northern United States, showing high-stepping horses in a flat park-style saddle at fairs was one way breeders would promote their horses.

Saddle seat is a style of English riding that differs considerably from other styles such as hunt seat and dressage. To the casual observer the rider sits well back in the saddle, carrying his or her hands higher than in other disciplines. Riders in equitation classes are penalized for leaning forward to any significant degree. However, like any other riding discipline, the position of the rider reflects the desired position of the horse. The rider must make the riding look effortless, and stay still and well-formed on the horse, sitting upright, with shoulders back and posting that is graceful and quiet. In saddle seat, high-stepping gaits are required of the horses shown, and the rider's position, behind the center of balance of the animal, allows the riding aids to be used to encourage front leg action in the horse.

Horse breeds usually shown saddle seat style typically have upright necks and free-moving, animated gaits. Several breeds do well in this discipline, with the most well-known being the American Saddlebred. Other breeds commonly exhibited in saddle seat style include Arabians, Morgans, Tennessee Walking Horses, and assorted partbred or crossbreds derived from these breeds, such as Spotted Saddle Horses, National Show Horses, and Racking Horse. In addition, Hackneys, Dutch Harness Horses, Paso Finos, Missouri Foxtrotters, and Rocky Mountain Horses are sometimes shown in this discipline.

The trot or gait for applicable breeds and divisions is generally considered to be the most prized gait. The 2020 United States Equestrian Federation (USEF) rule book defines movement for American Saddlebred and Half-American Saddlebred horses to be "clean, rhythmic and fluid action which is straight and true". Saddle seat horses should appear to be energetic and pleasant, while responsive to the exhibitor.

In the United States, the United States Equestrian Federation (USEF) creates and maintains the rules for most breeds shown in saddle seat competition.

Classes under saddle may include: