The Nyangatom (sometimes written Inyangatom, also known as Donyiro or Bumé) are a Nilotic ethnic group inhabiting southwestern Ethiopia and southeastern South Sudan. Numerically small and bellicose, they tend herds in a particularly inhospitable part of the disputed Ilemi Triangle.

The Nyangatom are related to the Toposa, their only friendly neighbours, in the extreme southeast of South Sudan. Their language is one of the Eastern Nilotic languages, closely related to Karimojong, and Teso of Uganda, Toposa and Turkana; these languages together form the cluster of Teso-Turkana languages.

They are called by the pejorative exonym Bume meaning "the smelly ones" by their neighbours (all but one ethnic group in the region being their enemies) such as the Suri and Turkana in the Omo valley.

Since the 1990s they have been armed with automatic weapons from Ethiopia because of their dispute with the Turkana. They struggle to get water, as they have to dig wells, whereas other local ethnic groups just go to the rivers. Food is often scarce; the men herd animals, while doing this they must have guns (commonly used guns are AK-47s, smuggled in from the Sudan) ready at all time, to protect their cattle from violent raiders which can strike at any time. While herding their animals the men live on a staple of milk and blood taken from their cows (without harming them seriously). Upon killing an enemy they scar themselves repeatedly to stop the bad blood from magically killing them. They are blessed and have their names changed when they kill.^{[citation needed]}