The Luo are an ethnic linguistic group

Dialect continuum

A dialect continuum, or dialect area, was defined by Leonard Bloomfield as a range of dialects spoken across some geographical area that differ only slightly between neighboring areas, but as one travels in any direction, these differences accumulate such that speakers from opposite ends of the...

 located in an area that stretches from South Sudan

South Sudan

South Sudan , officially the Republic of South Sudan, is a landlocked country located in the Sahel region of northeastern Africa. It is also part of the North Africa UN sub-region. Its current capital is Juba, which is also its largest city; the capital city is planned to be moved to the more...

 and Ethiopia

Ethiopia

Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...

 through northern Uganda

Uganda

Uganda , officially the Republic of Uganda, is a landlocked country in East Africa. Uganda is also known as the "Pearl of Africa". It is bordered on the east by Kenya, on the north by South Sudan, on the west by the Democratic Republic of the Congo, on the southwest by Rwanda, and on the south by...

 and eastern Congo (DRC), into western Kenya

Kenya

Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...

, and ending in the upper tip of Tanzania

Tanzania

The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...

. These people speak an Eastern Sudanic

Eastern Sudanic languages

Ehret 2001 [1984]Ehret, published in 2001 but circulating in manuscript form since at least 1984, calls the family "Eastern Sahelian", and idiosyncratically adds the Kuliak languages and Berta, which Bender assigns to higher-level branches of Nilo-Saharan, and reassigns Nyima to the southern branch...

 (Nilotic

Nilotic languages

The Nilotic languages are a group of Eastern Sudanic languages spoken across a wide area between southern Sudan and Tanzania by the Nilotic peoples, particularly associated with cattle-herding...

) language, a branch of the Nilo-Saharan

Nilo-Saharan languages

The Nilo-Saharan languages are a proposed family of African languages spoken by some 50 million people, mainly in the upper parts of the Chari and Nile rivers , including historic Nubia, north of where the two tributaries of Nile meet...

 language family. According to various classification schemes, they are sometimes referred to as River-Lake Nilotes

Nilotic

Nilotic people or Nilotes, in its contemporary usage, refers to some ethnic groups mainly in South Sudan, Uganda, Kenya, and northern Tanzania, who speak Nilotic languages, a large sub-group of the Nilo-Saharan languages...

 or Western Nilotes, which also includes the Dinka–Nuer language group.