This present work is to investigate the antibacterial activity of CeO2 nanoparticles on five foodborne pathogens. Low-temperature solid-state reactions were used to create co-doped CeO2 nanoparticles (Co-CeO2 NPs). In the current work, the impact of Co-doping on polycrystalline CeO2 samples synthesized using the co-precipitation method at room temperature for Co-doping concentrations of 0.5%, 1%, 3%, and 5% is discussed. Rietveld refinement of the X-ray diffraction patterns confirms that the Co-doped CeO2 samples have a face-centred cubic structure. This shows that the Co ions have been successfully integrated into the CeO2 lattice. Also, the UV-Vis-NIR absorption spectra confirm that redshifts do happen in the Co-doped CeO2 samples, which shows that the band gap energy decreases as the number of Co ions grows. In an antibacterial test against five pathogenic microbes, S. aureus, M. luteus, Enterobacter aerogenes, S. typhi, and Pseudomonas aeruginosa, Co-doped cerium oxide nanoparticles significantly slowed the growth of all five pathogens, both in liquid and solid growth conditions. These results show that Co-doped CeO2 nanoparticles have strong antibacterial properties against foodborne pathogens. This suggests that they could be used as promising bionanomaterials for in vivo therapeutic uses.