The hamadryas baboon (Papio hamadryas) is a species of baboon from the Old World monkey family. It is the northernmost of all the baboons, being native to the Horn of Africa and the southwestern region of the Arabian Peninsula. These regions provide habitats with the advantage for this species of fewer natural predators than central or southern Africa where other baboons reside. The hamadryas baboon was a sacred animal to the ancient Egyptians and appears in various roles in ancient Egyptian religion, hence its alternative name of 'sacred baboon'.

Apart from the striking sexual dimorphism (males are nearly twice as large as females, which is common to most baboons) this species also shows differences in coloration among adults. Adult males have a pronounced cape (mane and mantle), silver-white in color, which they develop around the age of ten, while the females are capeless and brown all over. Their faces range in color from reddish to tan to a dark brown.