[1] The sooty mangabey is native to tropical West Africa, being found in Guinea, Guinea-Bissau, Liberia, Senegal, Sierra Leone, and Ivory Coast.

Their faces are typically grayish pink, with darker fur along the forehead and ears;[1] given their diet of hard seeds and nuts, sooty mangabeys are observed to have strong molars.

[4] Sooty mangabeys typically live and forage in large, multi-male, multi-female groups of 70–120 individuals.

[15] Overall, however, females are found to be located in a more central spatial position within the group and better fed and rested than males, independent of ranking.

[18] As a result of these selective pressures, sooty mangabeys have evolved acoustically distinct alarm calls for different predator types.

[12] These calls are not vocalized specifically in favor of kin or cooperation partners[19] and in fact are used by other monkey species to avoid potential predators.

[16] In habituated sooty mangabeys, immigrant males new to the group have been found to attack infants, who would be defend by their mothers.

[28] Sooty mangabeys are naturally infected with a strain of Simian Immunodeficiency Virus (SIV), known as SIVsmm.

Due to extensive human-mangabey contact in sub-Saharan Africa, SIVsmm has jumped from this species into humans on many occasions, resulting in HIV-2 virus.