Olive baboons live in a variety of habitats across their broad range. Baboons are generally characterized as savanna species, inhabiting open grassland near wooded areas. While olive baboon are also found in moist, evergreen forests and near areas of human habitation and cultivation.
In Uganda olive baboons are commonly seen throughout the country in almost all rain forests and these include: Budongo forest in Murchison falls national, kibale national park, Queen Elizabeth national park and its neighboring protected areas (forest reserves). Most of the baboon are habituated in the east African Rift Valleys and are characterized by deep valleys that run parallel and which are separated by rocky cliffs. In these valleys, grassy plains are interspersed with occasional patches of shrub and only a few trees can survive in the rocky soils.
In Queen Elizabeth national park, Olive baboon habitats are characterized by dense forest surrounding the Ishasha River which slowly transitions from forest edge to coarse wet grass, then short grass with sandy areas, to low bush, and then to open grassland dotted with solitary trees and tall shrubs and bushes
At Kibale National Park, in western Uganda, olive baboons live in moist, evergreen forest bordered by swamp, grassland thickets, and secondary forests. Around the park, local families have cleared forest for subsistence agriculture. With a variety of cultivated crops growing near their habitat, olive baboons have become notorious crop-raiders, supplementing their diets with maize and bananas. Across the park, rainfall varies from 1100 to 1600 mm (3.61 to 5.25 ft) per year and annual average daily temperature ranges from 23.3 to 24.2° C (73.9 to 75.6° F) in this particular park.
In Uganda olive baboons spend up to 60% of their time in the rich, forested areas, home range size ranges between 3.88 and 5.18 km² (1.5 and 2 mi²) and day range length can be as short as a few hundred meters and up to 2.4 km.
Male olive baboons are twice as large as females. The average height for captive and wild males is about 700 mm (2.30 ft) and females measure about 600 mm
Wild male olive baboons weigh 24 kg, on average and wild females weigh 14.7 kg on average, where they live close to agricultural production and can raid crops, supplementing their natural diets with fruits, vegetables, and grains grown by local people, the average weights are slightly higher. Captive olive baboons weigh more than their wild counterparts, with the weight of captive males averaging 29 kg and females averaging 17 kg.