Background/Objectives: Antimicrobial resistance (AMR) is a global threat to human, animal, and environmental health. Among bacteria, E. coli is frequently used as a key indicator of AMR. Despite their genetic proximity to humans, studies on AMR in Non-Human Primates (NHPs) remain limited, particularly in semi-anthropized environments. This study aims to characterize the antibiotic resistance profiles and phylo-groups of E. coli isolated from NHPs and humans at a primatology center. Methods: A total of 143 stool samples were collected, including 125 from NHPs and 18 from humans. Isolates were cultured on Eosin Methylene Blue agar and then identified by MALDI-TOF mass spectrometry. Antibiotic susceptibility was assessed using the Kirby–Bauer disk diffusion method, with 30 antibiotics following CASFM-EUCAST recommendations. E. coli phylo-groups were characterized by quadruplex PCR according to the Clermont method, targeting the genes. Results: A total of 122 E. coli isolates (85.31%) were recovered, with comparable prevalence observed across NHPs and human staff. More than half of the isolates (55.74%) were resistant to at least one antibiotic tested, and 12.3% were classified as multi-drug resistant (MDR). Resistance rates of isolates in Mandrillus sphinx, Pan troglodytes, and humans were 50.6%, 57.7%, and 80.0%, respectively, with no significant statistical difference (p = 0.11). A single Extended-Spectrum Beta-Lactamase (ESBL) producing isolate was identified in the mandrill. Phylo-group analysis revealed the dominance of group A (50%), followed by groups B1, D, and C. Conclusions: Resistance profiles and phylo-group distribution among NHPs could suggest bacterial exchange and potential for cross-transmission of AMR within the shared environment.