The beagle is a breed of small scent hound, similar in appearance to the much larger foxhound. The beagle was developed primarily for hunting hare, known as beagling. Possessing a great sense of smell and superior tracking instincts, the beagle is the primary breed used as a detection dog for prohibited agricultural imports and foodstuffs in quarantine around the world. The beagle is intelligent and is a popular pet due to its size, good temper, and a lack of inherited health problems.

The modern breed was developed in Great Britain around the 1830s from several breeds, including the Talbot Hound, the North Country Beagle, the Southern Hound, and possibly the Harrier.

Beagles have been depicted in popular culture since Elizabethan times in literature and paintings and more recently in film, television, and comic books.