[3] Grant's gazelle shows high genetic variation among its populations, although there is no geographic isolation.

The differentiation of the species may have evolved during repeated expansion and contraction of arid habitats during the late Pleistocene era in which populations were possibly isolated.

A useful field mark is the white on the rump that extends over the top of the tail in Grant's but not Thomson's gazelles.

[3] Grant's gazelle are found in several countries in East Africa, including Ethiopia, Kenya, South Sudan and Tanzania, where they live in small to midsized herds, separated into females with juveniles and bachelor groups; during the mating season, when males become territorial and protective over a harem of females to breed with, bachelor herds briefly married disperse before tensions die-down again.

Confrontations between hormonal males rarely end in violence or death, with the 'loser' simply fleeing.

Grant's gazelle prefer living on short, grassy plains where they can graze, but can also be found browsing and foraging in more sparse, arid scrublands; they avoid areas with excessively high, untrimmed grass with compromised visibility of predators.

[10] They are sometimes seasonally migratory, but do not travel along the same routes as most of the other savanna ungulates, such as the Cape buffalo, plains zebra, Thomson's gazelle and the white-bearded gnu, which are all far more susceptible to dehydration.

Grant's gazelle can subsist on vegetation in waterless, semiarid areas, where they face considerably less resource competition.

The most common predators of the Grant's gazelle are the cheetah[11] and African wild dog; the typical predatory threats of hyenas, leopards, and lions are also ever-present.

At rivers, streams and some lakes, Nile crocodiles are a threat to nearly any mammal (excluding rhinos, hippos or elephants) that is unaware and comes to drink or cross to the other side.

Hippopotamus, while not carnivorous or outwardly predatory, are nonetheless extremely volatile beings with massive mouths and teeth, and are known to aggressively chase any other animal within their territory, including humans, at times resulting in the victim's death; a video was uploaded to YouTube of an apparently lost Grant's gazelle attempting to swim across a river filled with dozens of hippos, all of which responded with hostility.

Another video showed a Grant's gazelle attempting to flee a pursuing carnivore by retreating to the water, only to be attacked and killed by a hidden submerged hippopotamus.

[18] One way the Grant's gazelle withstands dehydration and heat stress is by being very efficient in digesting dry matter.

Grant's gazelles consume a smaller amount of food than domesticated animals, but they are better-suited for extreme environments because they derive protein from forage more quickly.

[19] The Grant's gazelle's diet may be responsible for the slow growth rates of browsed plants.

In dry seasons, gazelles move deep into dense brush and wait for the next rains.

[14] They will eat red oat grass and small, tough plants,[21] which are avoided by the other ungulates.