The Kipsigis, are a South Eastern Nilotic people who live in Kenya and Tanzania and are a part of the Kalenjin-speaking group of peoples who alongside other Highland Nilotes of the African Great Lakes Region make up the Kalenjin ethnic group. They live in close relation and association with the Nandi. They are structurally heterogeneous with an amalgamation of 'ortinwek' from Nandi, Okieik, Maasai, Kisii, Luo and aboriginal ethnicities of Kenya.
The Kipsigis people speak the Kipsigis language; Nilotic language which falls under the Nandi-Markweta cluster of the Kalenjin languages.
In the late 19th century AD, the Kipsigis were eponymised as the Lumbwa, a name which is of Maasai origin, which was adopted by the European colonial government for administrative purpose.
The Kipsigis together with other linguistically and culturally related peoples now identify as Kalenjin, an identity they have been collectively using since the 1950s. The Kipsigis people in census and other statistics are the most populous compared to their akin clans of Kalenjin.