Nyanza Province of Kenya, is one of Kenya's eight administrative provinces. It is located in the southwest part of Kenya around Lake Victoria. Nyanza includes part of the eastern edge of Lake Victoria and is inhabited predominantly by the Luo. There are also Bantu-speaking tribes such as the Gusii, the Kuria and a few traces of the Luhya living in the province. The province derives its name from Nyanza, a Bantu word which means a large mass of water.

The provincial capital is Kisumu, the third largest city in Kenya. The province has a population of 4,392,196 (as of 1999) within an area of 16,162 km².

The climate is tropical humid.

Initially, Nyanza had four administrative districts. Since the 1990s, the province has been further divided into the following districts:

District (capital):
Bondo (Bondo) · Gucha (Ogembo ^a) · Homa Bay (Homa Bay) · Kisii (Kisii) ^b · Kisumu (Kisumu) · Kuria (Kehancha) · Migori (Migori) · Nyamira (Nyamira) ^c · Nyando (Awasi) · Rachuonyo (Oyugis) · Siaya (Siaya) · Suba (Mbita)