In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other forages into meat, milk, wool and other animal products, often on land unsuitable for arable farming.

Farmers may employ many different strategies of grazing for optimum production: grazing may be continuous, seasonal, or rotational within a grazing period. Longer rotations are found in ley farming, alternating arable and fodder crops; in rest rotation, deferred rotation, and mob grazing, giving grasses a longer time to recover or leaving land fallow. Patch-burn sets up a rotation of fresh grass after burning with two years of rest. Conservation grazing proposes to use grazing animals to improve the biodiversity of a site, but studies show that the greatest benefit to biodiversity comes from removing grazing animals from the landscape.

Grazing has existed since the beginning of agriculture; sheep and goats were domesticated by nomads before the first permanent settlements were constructed around 7000 BC, enabling cattle and pigs to be kept.

Livestock grazing contributes to many negative effects on the environment, including deforestation, extinction of native wildlife, pollution of streams and rivers, overgrazing, soil degradation, ecological disturbance, desertification, and ecosystem stability.