Lake Naivasha is a freshwater lake in Kenya, outside the town of Naivasha in Nakuru County, which lies north west of Nairobi. It is part of the Great Rift Valley. The name derives from the local Maasai name Nai'posha, meaning "rough water" because of the sudden storms which can arise.
The lake is home to a variety of types of wildlife including over 400 different species of bird and a sizable population of hippos. The fish community in the lake has been highly variable over time, influenced by changes in climate, fishing effort and the introduction of invasive species. The most recent shift in the fish population followed the accidental introduction of common carp in 2001. Nine years later, in 2010, common carp accounted for over 90% of the mass of fish caught in the lake.
There are two smaller lakes in the vicinity of Lake Naivasha: Lake Oloiden and Lake Sonachi (a green crater lake). The Crater Lake Game Sanctuary lies nearby, while the lake shore is known for its population of European immigrants and settlers.