The habitat preferences of the Desert Warthog remain poorly understood (Grubb and d'Huart 2013, De Jong and Butynski 2014). Locality records, combined with several surveys in Kenya, indicate preference for low altitude semi-arid areas with sandy soils. Vegetation types range from xerophylous bush and open woodland, to sub-desert steppe. Absent from forest. (d'Huart and Grubb 2001, Grubb and d'Huart 2013, De Jong and Butynski 2014, De Jong et al. in prep.). Typically avoids hilly terrain and areas with a mean annual rainfall <100 mm or >750 mm (Grubb and d'Huart 2013, De Jong et al. in prep.). Mainly occupies areas with mean annual temperature >20°C, but in north Somalia occurs where mean annual temperature is as low as about 16 °C (De Jong et al. in prep.). The Desert Warthog is dependent on surface water, nutritious grass, shade, and shelter (Grubb and d'Huart 2010, T. Butynski and Y. de Jong pers. obs.). It grazes predominantly on nutritious grasses (Nyafu 2009, Y. de Jong and T. Butynski pers. obs.). The diet is poorly known, but comprised of grass leaves, bulbs, and tubers (De Jong and Butynski 2014), and expected to include rhizomes, fruits, invertebrates, and leaves from forbs and woody plants (T. Butynski, J.P. d’Huart and Y. de Jong pers. obs.).

The Somali Warthog is distributed east of the Eastern (Gregory) Rift Valley in the Horn of Africa and Kenya. It is known to occur in north and south Somalia, southeast and south Ethiopia, and central, east, southeast, and extreme north Kenya (d'Huart and Grubb 2001, Culverwell et al. 2008, De Jong et al. 2009, De Jong and Butynski 2014, De Jong et al. in prep.). Probably present over almost all of Somalia, but information to support this opinion is lacking. Most records are between about sea level to 1,000 m asl. Highest altitudinal record is 1,690 m asl (north Somalia; D. Mallon pers. comm.). Extent of occurrence, as currently known, is c. 320,000 km² (De Jong et al. in prep.). Actual extent of occurrence is probably much greater than this.

Sympatric with the Common Warthog (Phacochoerus africanus) in parts of north Somalia, and in parts of central, east, and southeast Kenya (De Jong and Butynski 2014, De Jong et al. in prep.).

The Cape Warthog is distributed in South Africa, southeast former Cape Province and, apparently, in adjacent parts of KwaZulu-Natal. Extinct since the 1870s (d'Huart and Grubb 2001, Grubb and d'Huart 2010).