The Wanjii Hydroelectric Power Station is a hydroelectric power station in Kenya.
The power station is located near the village of Kambirwa, in Muranga County, approximately , by road, northeast of Nairobi, the capital and largest city in Kenya. The coordinates of Wanjii Power Station are: 0ð44'58.0"S, 37ð10'29.0"E (Latitude:-0.749437; Longitude:37.174731).
The power station draws its waters from the Mathioya River and the Maragwa River stored in the Wanjii Reservoir on the Maragwa River.
Wanjii Hydroelectric Power Station is owned by Kenya Electricity Generating Company, a parastatal company of the government of Kenya.