The Aylesbury duck is a breed of domesticated duck, bred mainly for its meat and appearance. It is a large duck with pure white plumage, a pink bill, orange legs and feet, an unusually large keel, and a horizontal stance with its body parallel to the ground. The precise origins of the breed are unclear, but raising white ducks became popular in Aylesbury, Buckinghamshire, England, in the 18th century owing to the demand for white feathers as a filler for quilts. Over the 19th century selective breeding for size, shape and colour led to the Aylesbury duck.
Duck rearing became a major industry in Aylesbury in the 19th century. The ducks were bred on farms in the surrounding countryside. Fertilised eggs were brought into the town's "Duck End", where local residents would rear the ducklings in their homes. The opening of a railway to Aylesbury in 1839 enabled cheap and quick transport to the markets of London, and duck rearing became highly profitable. By the 1860s the duck rearing industry began to move out of Aylesbury into the surrounding towns and villages, and the industry in Aylesbury itself began to decline.
In 1873 the Pekin duck was introduced to the United Kingdom. Although its meat was thought to have a poorer flavour than that of the Aylesbury duck, the Pekin was hardier and cheaper to raise. Many breeders switched to the Pekin duck or to Aylesbury-Pekin crosses. By the beginning of the 20th century competition from the Pekin duck, inbreeding, and disease in the pure-bred Aylesbury strain and the rising cost of duck food meant the Aylesbury duck industry was in decline.
The First World War badly damaged the remaining duck industry in Buckinghamshire, wiping out the small scale producers and leaving only a few large farms. Disruption caused by the Second World War further damaged the industry. By the 1950s only one significant flock of Aylesbury ducks remained in Buckinghamshire, and by 1966 there were no duck-breeding or -rearing businesses of any size remaining in Aylesbury itself. Although there is only one surviving flock of pure Aylesbury ducks in the United Kingdom and the breed is critically endangered in the United States, the Aylesbury duck remains a symbol of the town of Aylesbury, and appears on the coat of arms of Aylesbury and on the club badge of Aylesbury United.