The County Government of Uasin Gishu is the creation of the Constitution of Kenya 2010 and successor of the defunct City Council of Uasin Gishu. It operates under the auspices of the Cities and Urban Areas Act, The Devolved Governments Act and a host of other Acts. 

The County Government of Uasin Gishu is charged with the responsibility of providing a variety of services to residents within its area of jurisdiction. These include the services that were hitherto provided by the defunct City Council and the ones that have been transferred from the national government. The former include Physical Planning, Public Health, Social Services and Housing, Primary Education Infrastructure, Inspectorate Services, Public Works, Environment Management while the latter include Agriculture, Livestock Development and Fisheries, Trade, Industrialization, Corporate Development, Tourism and Wildlife, Public Service Management.

Its name comes from the Illwuasin-kishu Maasai clan. The land was the grazing area of the clan. They surrendered the land to the colonial government in the Anglo-Maasai agreement of 1911, and were subsequently pushed towards Trans Mara. The plateau that they once occupied was then registered in its Anglicised version, Uasin Gishu