A working animal is an animal, usually domesticated, that is kept by humans and trained to perform tasks. Some are used for their physical strength (e.g. oxen and draft horses) or for transportation (e.g. riding horses and camels), while others are service animals trained to execute certain specialized tasks (e.g. hunting and guide dogs, messenger pigeons, and fishing cormorants). They may also be used for milking or herding. Some, at the end of their working lives, may also be used for meat or leather.

The history of working animals may predate agriculture as dogs were used by hunter-gatherer ancestors; around the world, millions of animals work in relationship with their owners. Domesticated species are often bred for different uses and conditions, especially horses and working dogs. Working animals are usually raised on farms, though some are still captured from the wild, such as dolphins and some Asian elephants.

People have found uses for a wide variety of abilities in animals, and even industrialized societies use many animals for work. People use the strength of horses, elephants, and oxen to pull carts and move loads. Police forces use dogs for finding illegal substances and assisting in apprehending wanted persons, others use dogs to find game or search for missing or trapped people. People use various animals—camels, donkeys, horses, dogs, etc.—for transport, either for riding or to pull wagons and sleds. Other animals, including dogs and monkeys, help disabled people.

On rare occasions, wild animals are not only tamed, but trained to perform work—though often solely for novelty or entertainment, as such animals tend to lack the trustworthiness and mild temper of true domesticated working animals. Conversely, not all domesticated animals are working animals. For example, while cats may catch mice, it is an instinctive behavior, not one that can be trained by human intervention. Other domesticated animals, such as sheep or rabbits, may have agricultural uses for meat, hides and wool, but are not suitable for work. Finally, small domestic pets, such as most small birds (other than certain types of pigeon) are generally incapable of performing work other than providing companionship.

Some animals are used due to sheer physical strength in tasks such as ploughing or logging. Such animals are grouped as a draught or draft animals. Others may be used as pack animals, for animal-powered transport, the movement of people and goods. Together, these are sometimes called beasts of burden. Some animals are ridden by people on their backs and are known as mounts. Alternatively, one or more animals in harness may be used to pull vehicles.

Riding animals are animals that people use as mounts in order to perform tasks such as traversing across long distances or over rugged terrain, hunting on horseback or with some other riding animal, patrolling around rural and/or wilderness areas, rounding up and/or herding livestock or even for recreational enjoyment. They mainly include equines such as horses, donkeys, and mules; bovines such as cattle, water buffalo, and yak. In some places, elephants, llamas and camels are also used. Dromedary camels are in arid areas of Australia, North Africa and the Middle East; the less common Bactrian camel inhabits central and East Asia; both are used as working animals. On occasion, reindeer, though usually driven, may be ridden.

Certain wild animals have been tamed and used for riding, usually for novelty purposes, including the zebra and the ostrich. Some mythical creatures are believed to act as divine mounts, such as garuda in Hinduism (See vahana for divine mounts in Hinduism) and the winged horse Pegasus in Greek mythology.

Pack animals may be of the same species as mounts or harness animals, though animals such as horses (especially packhorses), mules, donkeys, reindeer and both types of camel may have individual bloodlines or breeds that have been selectively bred for packing. Additional species are only used to carry loads, including llamas in the Andes.