Copper oxide thin films doped with Ce³⁺ ions were prepared by a sol–gel dip-coating method. XRD patterns and FTIR spectroscopy disclosed dual-phase copper oxide (CuO-Cu₂O) with Ce doping. Morphology of films changed from irregular grain structure to cuboids. The bandgap of thin films decreased with an increase in Ce dopant. AC conductivity decreased with doping of Ce up to 2% while an increase in Ce concentration to 5% enhanced it. Photocatalytic activity increases with an increase in cerium dopant percentage. The probe of the antibacterial activity displayed that 3 at. wt. % Ce-doped copper oxide exhibits the best bactericidal effect against four bacterial strains. The improved antibacterial activity of the Ce doped copper oxide can replace silver for wound dressings, bone implants, and dental fillings.