The Cleveland Bay is breed of horse originating in Great Britain during the Middle Ages. It is a well-muscled horse, with legs that are strong but short in relation to the body. The horses are always bay in color. They are the oldest established horse breed in England, and the only non-heavy horse developed in Great Britain. They were originally developed for use as pack horses, where they gained their nickname of "Chapman Horses". Over the years, the breed became lighter in frame as they were employed more as carriage and riding horses. The popularity of the Cleveland Bay has greatly fluctuated since it was first imported to the United States in the early 1800s. Despite serious declines in the population after World War II, the breed has experienced a resurgence in popularity since the 1980s.
The breed has also been used to develop and improve several warmblood and draft horse breeds. Today they are used for farm and driving, as well as under-saddle work. They are used especially for fox hunting, both pure blooded and when crossed with Thoroughbreds. The Cleveland Bay is a rare breed, and both the United Kingdom-based Rare Breeds Survival Trust and the United States-based American Livestock Breeds Conservancy consider the population to be at critical limits for extinction.