This work reports the detailed structural characterization of Zn2+ ion-substituted cobalt ferrite nanoparticles (CFO NPs; Co1−xZnxFe2O4; x = 0.00, 0.25, 0.50, and 0.75), prepared using a facile sol–gel method. It correlates structural changes with magnetic and dielectric properties. The as-synthesized samples were investigated by X-ray diffraction (XRD) analysis, BET surface area analyzer, energy-dispersive X-ray (EDX), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Mössbauer spectroscopy, and impedance analyzer. The pristine sample