a group of languages representing the most diverse of the major divisions within the Nilo-Saharan language family (Nilo-Saharan languages). These languages are spoken from southern Egypt in the north to Tanzania in the south and from Ethiopia and Eritrea in the east to Chad in the west. During the first half of the 20th century, the term Eastern Sudanic was also used to refer to the eastern members of a larger grouping of languages then called Sudanic.

Nilotic (Nilotic languages) and Nubian (Nubian languages) are the two most important groups of the Eastern Sudanic languages. The remaining groups are Surmic (Surmic languages), Eastern Jebel (Eastern Jebel languages), Taman (Taman languages), Daju (Daju languages), Nera, Kuliak, Nyimang and Afitti (or Dinik), and Temein and Keiga Jirru.

Of these, the Nyimang and Afitti (or Dinik) and the group that includes Temein and Keiga Jirru languages are spoken (together with the Nubian languages) in the Nuba Hills. The Kuliak languages, spoken by only a few small communities in Uganda known as Ik (Teuso), Soo, and Tepes, are surrounded by speakers of Nilotic languages. Farther northeast, in the border area of The Sudan and Ethiopia, other Nilo-Saharan languages are found. In this linguistically complex area, several Nilo-Saharan groups—Surmic (or Surma, also known as Didinga-Murle, after two of its members), Eastern Jebel, and Berta, in the angle formed by the Blue Nile in Ethiopia and the Sudan border—are interspersed with Afro-Asiatic (Afro-Asiatic languages) groups (mainly groups speaking languages belonging to the Cushitic and Omotic branches of that family). The territory of the Nera (also known as Barea, a name they consider to be pejorative), who were first mentioned in a 4th-century-AD inscription by King Ezana of Aksum, adjoins that of the Eritrean speakers of Kunama and Ilit languages.