The Serengeti (Pron:ˌserənˈgeti) ecosystem is a geographical region in Africa. It is located in north Tanzania and extends to south-western Kenya between latitudes 1 and 3 S and longitudes 34 and 36 E. It spans some 30,000 km² (12,000 sq mi). The Kenyan part of the Serengeti is known as Maasai (Masai) Mara.

The Serengeti hosts the largest terrestrial mammal migration in the world, which helps secure it as one of the Seven Natural Wonders of Africa, and one of the ten natural travel wonders of the world. The Serengeti is also renowned for its large lion population and is one of the best places to observe prides in their natural environment. The region contains the Serengeti National Park in Tanzania and several game reserves. Serengeti is derived from the Maasai language, Maa; specifically, "Serengit" meaning "Endless Plains".

Approximately 70 larger mammal and some 500 avifauna species are found there. This high diversity in terms of species is a function of diverse habitats ranging from riverine forests, swamps, kopjes, grasslands and woodlands. Blue wildebeests, gazelles, zebras and buffalos are some of the commonly found large mammals in the region.