A halter (US) or headcollar (UK) is headgear that is used to lead or tie up and, occasionally, other animals; it fits behind the ears (behind the ), and around the muzzle. To handle the animal, usually a lead rope or lead shank is attached. On smaller animals, such as dogs, a leash is attached to the halter.
Halters may be as old as the early domestication of animals, and their history is not as well studied as that of the bridle or hackamore. The word "halter" derives from the Germanic words meaning "that by which anything is held."
A halter is used to lead and tie up an animal. It is used on many different types of . Halters are most closely associated with Equidae such as horses, donkeys, and mules. However, they are also used on farm animals such as cattle and goats and other working animals such as camels, llamas, and yaks. Halters generally are not used on elephants or on predators, though there are halters made for dogs.
Halters are often plain in design, used as working equipment on a daily basis. In addition to the halter, a lead line, lead shank or lead rope is required to actually lead or tie the animal. It is most often attached to the halter at a point under the jaw, or less often, at the cheek, usually with a snap, but occasionally spliced directly onto the halter. A standard working lead rope is approximately 9 to 12 feet (2.7 to 3.7 m) long.
However, specially designed halters, sometimes highly decorated, are used for in-hand or "halter" classes at horse shows and in other . When an animal is shown in an exhibition, the show halter is fitted more closely than a working halter and may have a lead shank that tightens on the head so that commands from the handler may be more discreetly transmitted by means of the leadline. A shank that tightens on the animal's head when pulled is not used for tying the animal.