Great apes and other primates are discussed in this chapter in details related to their biological evolution in ecological niches based on evolved diets. Consideration is given to great apes as ecosystem engineers in contrast to modern humans. Connections, parallels, and differences are drawn between great ape and human diets. Insectivory, folivory, and frugivory among apes and humans are considered. Food preferences for great apes are enumerated. Behavioral ecology is weighed in terms of apes hunting for meat. Primate dental morphology is reviewed as well as food distribution and eating behaviors. Detail is provided on the particular, preferred foods of chimpanzees and bonobos, gorillas, and orangutans in their ecosystem habitats. Close attention is paid to the diets of captive great apes in mimicking forest diets. Philosophical consideration is given to the subjects of animals as food and ape/human culture.