Giant forest hogs occur in west and central Africa, where they are largely restricted to the Guinean and Congolese forests. They also occur more locally in humid highlands of the Rwenzori Mountains and as far east as Mount Kenya and the Ethiopian Highlands. They are mainly found in forest-grassland mosaics, but can also be seen in wooded savanna and subalpine habitats at altitudes up to . They are unable to cope with low humidity or prolonged exposure to the sun, resulting in them being absent from arid regions and habitats devoid of dense cover.