Kisumu County is one of 47 counties in the Republic of Kenya. Its borders follow those of the original Kisumu District, one of the former administrative districts of the former Nyanza Province in western Kenya. Its headquarters is Kisumu City. It has a population of 968,909 (according to the 2009 National Census). The land area of Kisumu County totals 2085.9 km 2.
Kisumu County's neighbours are Siaya County to the West Vihiga County to the North, Nandi County to the North East and Kericho County to the East. Its neighbour to the South is Nyamira County and Homa Bay County is to the South West. The county has a shoreline on Lake Victoria, occupying northern, western and a part of the southern shores of the Winam Gulf.
The name Kisumu comes from the Luo word "Kisuma"Kikelo. Generally, Kisuma means "a place where people meet to exchange goods" but it does not necessarily mean the same word as "market" (chiro in Luo). The term was especially used during famine where a person could " visit" relatives who had some short of harvest where the "visitor" when going back to his/her place could be "escorted with" or given some grains and dried meat (aliya in Luo). The word originally comes from the verb "sumo", which means "getting material want through exchange or as an assistance when one has minimal ability then, it should be differentiated from 'fulo' where one rummages through the farm of someone else after the harvest to pick dropped or omitted crops to collect and take home for consumption". When Europeans and Indians came to the area of the present-day city of Kisumu, pronouncing the name "Kisuma" correctly proved difficult, and the name evolved into the current Kisumu. The local people however, now popularly call the place "Kisumo".