Kisumu is the third-largest city in Kenya and the third-largest city in the Lake Victoria Basin. It is located on the shores of Lake Victoria. It lies at the north-eastern edge of the Winam Gulf, a long, shallow arm that protrudes from the main body of Lake Victoria. Kisumu has moderate temperatures because of its elevation. Culturally, Kisumu serves as the headquarters of the Luo speaking people of East Africa. The metropolitan region comprises the city and its suburbs and satellite towns of Maseno, Kondele, and Ahero. Kisumu was the most prominent urban centre in the pre-colonial, post-colonial, and modern era for natives of Kavirondo region. It is one of the premier industrial and commercial centres in Kenya. The city is currently undergoing an urban rejuvenation of the downtown and lower town which includes modernising the lake front, decongesting main streets, and making the streets pedestrian-friendly.
Kisumu is officially known as Kisumu City. Kisumu port was founded in 1901 as the main inland terminal of the Uganda Railway named "Port Florence". Other names of the city includes Dala (Home of the Luos), Kisuma (place of barter trade), KC (short for Kisumu City), Odhumo (Nairobi sheng for Kisumu) and others.
Kisumu serves as the capital city of Kisumu County, Kenya and is an important link in the trade route between Lake Victoria and Mombasa because of its water and rail connections. It is also the chief terminus for the agricultural produce of Nyanza and Western provinces. It is the largest and most important city in the Western Kenya. Kisumu serves as a trading and transportation hub for the Great Lakes region in western Kenya. Kisumu International Airport has regular flights to Nairobi and other neighbouring cities. Trade is again growing around oil exports.
According to the United Nations, it is now recognised as a key city and a "Millennium City".
Kisumu has a population of over 397,957 people. Kisumu also forms part of the wider Kisumu metropolitan area which has a population of over 1,268,826 people.
The city has "Friendship" status with Cheltenham, United Kingdom and "sister city" status with Roanoke, Virginia and Boulder, Colorado, United States.