Feeding ontogeny in primates has three stages. In utero, nutrition is gained maternally. After birth, primates suckle. We know little about functional variation in these stages. The transition to adult feeding – highlighted by weaning – varies across species. Variation is tied to many socioecological and morphological influences across primates. Primate feeding apparatus ontogeny is affected by many factors. Diet exhibits a complex relationship with the clearest signal marked by rapid dental mineralization and eruption in folivorous strepsirrhines. Mineralization varies across primates. Emergence and eruption of postcanine teeth tends to follow size in both suborders with smaller taxa showing earlier emergence, the exception being rapid eruption in some folivores. Compared to teeth, less is known about the musculoskeletal ontogeny of the feeding apparatus. Most studies compare closely related species and link musculoskeletal robustness to challenging diets. Looking forward, better understanding of primate feeding apparatus growth will require improved samples (a challenge for long-lived species) and emphasis on the evolutionary significance of feeding throughout ontogeny.