This study aimed to prepare Ce1-xNixO2 (where × = 0.02, 0.04, and 0.06 w/w) nanoparticles (NPs) utilizing Acacia Concinna fruit extract as surfactant in a cost-efficient way. Sol-gel technique was used to synthesize both CeO2 and Ni-doped CeO2 NPs in a bio-synthesis method. XRD spectroscopy, FTIR, SEM, Raman spectroscopy, etc., were applied to characterize the NPs. XRD pattern showed a face-centered cubic fluorite-type structure for both CeO2 and Ni-doped CeO2 samples. It also revealed a peak shift (111) towards the lower 2θ angle for Ni-doped samples. The average crystallite size was calculated to be 22.7 nm for CeO2, ranging from 46.49 nm to 54.08 nm for Ni-doped CeO2 NPs. Raman spectroscopy showed the F2g vibrational mode of the cubic fluorite structure of pure and doped NPs at around 462 cm−1. SEM micrograph depicted porous network-like morphology for both samples. The characteristic absorption band shown for Ce-O at 849 cm−1 was verified by FT-IR analysis. The dielectric properties of NPsindicatedan increase in AC conductivity (σac), dielectric loss (∊’’), and dielectric permittivity (∊’) values, whereas a decrease in real impedance (Z’) was observed with a rise in doping concentration of Ni and were dependent on frequency.