An ambling gait or amble is any of several four-beat intermediate horse gaits, all of which are faster than a walk but usually slower than a canter and always slower than a gallop. Horses that amble are sometimes referred to as "gaited", particularly in the United States. Ambling gaits are smoother for a rider than either the two-beat trot or pace and most can be sustained for relatively long periods, making them particularly desirable for trail riding and other tasks where a rider must spend long periods in the saddle. Historically, horses able to amble were highly desired for riding long distances on poor roads. Once roads improved and carriage travel became popular, their use declined in Europe but continued in popularity in the Americas, particularly in areas where plantation agriculture was practiced and the inspection of fields and crops necessitated long daily rides.

The ability to perform an ambling gait is usually an inherited trait. In 2012, a DNA study found that horses from several gaited and harness racing breeds carried a mutation on the gene DMRT3, which controls the spinal neurological circuits related to limb movement and motion. In 2014, that mutation was found to originate in a single ancestor to all gaited horses. Some gaited breeds naturally perform these gaits from birth, others need to be trained to do them. Some breeds have individuals who can both amble and perform a trot or pace. In the Standardbred breed, the DMRT3 gene was also found in trotting horses, suggesting that it inhibits the ability to transition into a canter or gallop.

Though there are differences in footfall patterns and speed of the various gaits, historically they were collectively referred to as an "amble". The many different names for these gaits reflect the nuanced differences sought by aficionados of each particular breed, with traits considered desirable in one breed sometimes discouraged in another. Gaited breeds occur in many parts of the world, but are particularly prevalent in North and South America.