The goat or domestic goat (Capra hircus) is a species of goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (C. aegagrus) of Southwest Asia and Eastern Europe. The goat is a member of the family Bovidae, meaning it is closely related to the sheep. It was one of the first animals to be domesticated, in Iran around 10,000 years ago.

Goats have been used for milk, meat, wool, and skins across much of the world. Milk from goats is often turned into cheese. In 2022, there were more than 1.1 billion goats living in the world, of which 150 million were in India.

Goats feature in mythology, folklore, and religion in many parts of the world, including in the classical myth of Amalthea, in the goats that pulled the chariot of the Norse god Thor, in the Scandinavian Yule goat, and in Hinduism's goat-headed Daksha. In Christianity and Satanism, the devil is sometimes depicted as a goat. 

The Modern English word goat comes from Old English gāt "goat, she-goat", which in turn derives from Proto-Germanic *gaitaz (cf. Dutch/Frisian/Icelandic/Norwegian geit, German Geiß, and Gothic gaits), ultimately from Proto-Indo-European *ǵʰaidos meaning "young goat" (cf. Latin haedus "kid"). To refer to the male goat, Old English used bucca (cf. Dutch/Frisian bok, modern English buck) until ousted by hegote, hegoote ('he-goat') in the late 12th century. Nanny goat (adult female) originated in the 18th century, and billy goat (adult male) in the 19th century. Female goats, like other various animals, are also called does.

Castrated males are called wethers. While the words hircine and caprine both refer to anything having a goat-like quality, hircine is used most often to emphasize the distinct smell of domestic goats. A young goat i.e 'kid' in Kalimpong

Juvenile goats are called kids, a term derived from Old Norse kið, with the same meaning. It has been a slang term for human children since the 1590s, and established as an informal term since the 1840s.

Goats are among the earliest animals to have been domesticated by humans. A genetic analysis confirms the archaeological evidence that the wild bezoar ibex, found today in the Zagros Mountains, but formerly widespread in Anatolia, is the likely original ancestor of all or most domestic goats today.

Neolithic farmers began to herd wild goats primarily for easy access to milk and meat, as well as to their dung, which was used as fuel; and their bones, hair, and sinew were used for clothing, building, and tools. The earliest remnants of domesticated goats dating 10,000 years Before Present are found in Ganj Dareh in Iran.[12][13] Goat remains have been found at archaeological sites in Jericho, Choga Mami,[14] Djeitun, and Çayönü, dating the domestication of goats in Western Asia at between 8,000 and 9,000 years ago.[9] DNA evidence suggests that goats were domesticated around 10,000 years ago.[10] Historically, goat hide has been used for water and wine bottles in both traveling and transporting wine for sale, and to produce parchment.

Each breed of goat has specific weight ranges, which vary from more than 140 kg (310 lb) for bucks of larger breeds such as the Boer, to 20 to 27 kg (44 to 60 lb) for smaller does. Within each breed, different strains or bloodlines may have different recognized sizes. At the bottom of the size range are miniature breeds such as the African Pygmy, which stand 41 to 58 cm (16 to 23 in) at the shoulder as adults.

Most goats naturally have two horns, their shape and size depending on the breed.[18] There have been incidents of polycerate goats (having as many as eight horns), although this is a genetic rarity. Unlike cattle, goats have not been successfully bred to be reliably polled, as the genes determining sex and those determining horns are closely linked. Breeding together two genetically polled goats results in a high number of intersex individuals among the offspring, which are typically sterile. Their horns are made of living bone surrounded by keratin and other proteins, and are used for defense, dominance, territoriality, and thermoregulation. Both male and female goats may have beards, and many types of goat (most commonly dairy goats, dairy-cross Boers, and pygmy goats) may have wattles, one dangling from each side of the neck. Goats have horizontal, slit-shaped pupils, allowing them to see well by both night and day, and giving them a wide field of vision on either side to detect predators, while avoiding being dazzled by sunlight from above. Goats have no tear ducts.

Goats are ruminants. They have a four-chambered stomach consisting of the rumen, the reticulum, the omasum, and the abomasum. As with other mammal ruminants, they are even-toed ungulates. The females have an udder consisting of two teats, in contrast to cattle, which have four teats. An exception to this is the Boer goat, which sometimes may have up to eight teats. Goats are diploid with two sets of 30 chromosomes.

Goats are reputed to be willing to eat almost anything. They are browsing animals, not grazers like cattle and sheep, and (coupled with their highly curious nature) will chew on and taste anything resembling plant matter to decide whether it is good to eat, including cardboard, clothing and paper.

The digestive physiology of a very young kid (like the young of other ruminants) is essentially the same as that of a monogastric animal. Milk digestion begins in the abomasum, the milk having bypassed the rumen via closure of the reticuloesophageal groove during suckling. At birth, the rumen is undeveloped, but as the kid begins to consume solid feed, the rumen soon increases in size and in its capacity to absorb nutrients.

The adult size of a particular goat is a product of its breed (genetic potential) and its diet while growing (nutritional potential). As with all livestock, increased protein diets (10 to 14%) and sufficient calories during the prepuberty period yield higher growth rates and larger eventual size than lower protein rates and limited calories. Large-framed goats, with a greater skeletal size, reach mature weight at a later age (36 to 42 months) than small-framed goats (18 to 24 months) if both are fed to their full potential. Large-framed goats need more calories than small-framed goats for maintenance of daily functions.