Teso is a language spoken by perhaps 1,300,000 people in Uganda and Kenya.

One of the Eastern Nilotic group of the Nilo-Saharan language family, Teso is traditionally said to have been brought to eastern Uganda in a migration from further east, led by the cultural hero Teso.

At the end of the 19th century, Ganda speaking agents brought most of Teso territory under the British protectorate of Uganda, and reorganized its political system. From then onwards, Teso has adopted an increasing number of Ganda loanwords. Other Bantu languages, such as Luyia, have also influenced Teso.

Under British rule a Teso alphabet was developed, under missionary influence, by the Teso Orthography Committee. The Christian sects could not agree over spelling, however: Catholic and Protestant orthographies differ.

Teso is also the name of a group of people in Kenya. The Nilotes, or Nilotic Tribes are divided into Riverlake Nilotes, Plain Nilotes and Highland Nilotes. The Plain Nilotes are made up of the Teso, Turkana and the Maa-group.
