The Niger–Congo languages constitute one of the world's major language families, and Africa's largest in terms of geographical area, number of speakers, and number of distinct languages. They may constitute the world's largest language family in terms of distinct languages, although this question is complicated by ambiguity about what constitutes a distinct language. Most of the most widely spoken indigenous languages of Subsaharan Africa belong to this group. A common property of many Niger–Congo languages is the use of a noun class system. The most widely spoken Niger–Congo languages by number of native speakers are Yoruba, Igbo, Fula and Shona and Zulu. The most widely spoken by total number of speakers is Swahili.

Niger–Congo as it is known today was only gradually recognized as a unity. In early classifications of African languages, one of the principal criteria used to distinguish different groupings was the languages' use of prefixes to classify nouns, or the lack thereof. A major advance came with the work of Koelle, who in his 1854 Polyglotta Africana attempted a careful classification, the groupings of which in quite a number of cases correspond to modern groupings. An early sketch of the extent of Niger–Congo as one language family can be found in Koelle's observation, echoed in Bleek (1856), that the Atlantic languages used prefixes just like many Southern African languages. Subsequent work of Bleek, and some decades later the comparative work of Meinhof, solidly established Bantu as a linguistic unit.

Niger (French pronunciation: [niʒɛʁ], but occasionally pronounced as /niːˈʒɛər/ or ⁱ/ˈnaɪdʒər/), officially the Republic of Niger, is a landlocked country in Western Africa, named after the Niger River. It borders Nigeria and Benin to the south, Burkina Faso and Mali to the west, Algeria and Libya to the north and Chad to the east. Niger covers a land area of almost 1,270,000 km², making it the largest nation in West Africa, with over 80 percent of its land area covered by the Sahara desert. The country's predominantly Islamic population of just above 15,000,000 is mostly clustered in the far south and west of the nation. The capital city is Niamey, located in the far southwest corner of Niger.

Niger is a developing country, and consistently ranks as one of the lowest ranks of the United Nations' Human Development Index (HDI), 186th of 187 countries in 2011. Much of the non-desert portions of the country are threatened by periodic drought and desertification. The economy is concentrated around subsistence and some export agriculture clustered in the more fertile south, and the export of raw materials, especially uranium ore. Niger remains handicapped by its landlocked position, desert terrain, poor education and poverty of its people, lack of infrastructure, poor health care, and environmental degradation.