Lake Baringo is, after Lake Turkana, the most northern of the Great Rift Valley lakes of Kenya, with a surface area of about 130 square kilometres (50 sq mi) and an elevation of about 970 metres (3,180 ft). The lake is fed by several rivers, El Molo, Perkerra and Ol Arabel, and has no obvious outlet; the waters are assumed to seep through lake sediments into the faulted volcanic bedrock. It is one of the two freshwater lakes in the Rift Valley in Kenya, the other being Lake Naivasha. It lies off the beaten track in a hot and dusty setting and over 470 species of birds have been recorded there, occasionally including migrating flamingos. A Goliath Heronry is located on a rocky islet in the lake known as Gibraltar.

The lake is part of the Great Rift Valley system. The Tugen Hills, an uplifted fault block of volcanic and metamorphic rocks, lies west of the lake. The Laikipia Escarpment lies to the east.

Water flows into the lake from the Mau Hills and Tugen Hills. It is a critical habitat and refuge for more than 500 species of birds and fauna, some of the migratory waterbird species being significant regionally and globally. The lake also provideds an invaluable habitat for seven fresh water fish species. One, Oreochromis alcalicus baringoensi, is endemic to the lake. Lake fishing is important to local social and economic development. Additionally the area is a habitat for many species of animals including the hippopotamus (Hippopotamus amphibius), crocodile (Crocodylus niloticus) and many other mammals, amphibians, reptiles and the invertebrate communities

Fish stocks in the lake are now low and water levels have been reduced by droughts and over-irrigation. The lake is commonly turbid with sediment, partly due to intense soil erosion in the catchment, especially on the Loboi Plain south of the lake.

The lake has several small islands, the largest being Ol Kokwe Island. Ol Kokwe, an extinct volcanic centre related to Korosi volcano north of the lake, has several hot springs and fumaroles, some of which have precipitated sulphur deposits. A group of hot springs discharge along the shoreline at Soro near the northeastern corner of the island.

Several important archaeological and palaeontological sites, some of which have yielded fossil hominoids and hominins, are present in the Miocene to Pleistocene sedimentary sequences of the Tugen Hills.

The main town near the lake is Marigat, while smaller settlements include Kampi ya Samaki and Loruk. The area is increasingly visited by tourists and is situated at the southern end of a region of Kenya inhabited largely by pastoralist ethnic groups including Il Chamus, Rendille, Turkana and Kalenjin. Accommodation (hotel, camping) is available at and near Kampi-Ya-Samaki on the midwestern shore. Boats to Ol Kokwe can be hired at Kampi-Ya-Samaki.