Anthropization affects wildlife feeding behavior due to changes in resource availability related to land use and land cover change. To better understand the ecological responses of wildlife towards anthropogenic change, it is essential to evaluate whether human land use, characterized by high human-modified food availability, has an impact on wildlife feeding ecology. The chacma baboon (Papio ursinus) is an interesting study subject for potential diet changes as it is largely present along a gradient of anthropized areas in Southern Africa. In this study, fecal samples from chacma baboon troops were collected in different habitats with distinct land uses (peri-urban, agricultural and natural forest habitat) in the Garden Route, South Africa, and their carbon (d13C) and nitrogen (d15N) isotopic ratios were measured. Results showed significant differences between d15N ratios according to land use, suggesting a shift towards higher protein intake in areas with human influence in comparison to natural forest habitats. The large majority of the collected samples reflected the C3 ecosystem of the Garden Route region, with the exception of some samples in peri-urban habitats showing higher d13C ratios, which could be associated with the consumption of anthropogenic foods (e.g. sugar or corn). The potential protein increase, as well as sources of C4 plants present in the diets in anthropized areas, suggest a dietary shift for this species between natural and transformed landscapes. In the future, it will be essential to determine whether and how the consumption of human-modified food could affect the health and associated fitness of chacma baboons.