At room temperature, different compositions of nanocrystalline Cu0.5Mg0.5Cr0.5CexFe1.5-xO4 (x = 0.0, 0.05, 0.10, 0.15) were prepared using the sol-gel method. Cubic spinel nanoparticles were confirmed through X-ray diffraction (XRD) measurements. The secondary phase of CeO2 was observed to increase in cerium content, as well as an increase in the lattice constant (7.831 Å to 7.881 Å) and a decrease in the crystalline size (28 nm to 26 nm) of the ferrites. TGA study revealed that the sample had a weight loss of up to 12.0 % and a thermal stability of 88.0 %. FTIR spectra showed the characteristic broad band between 500 and 1000 cm-1 for M-O bonding present in the ferrite sample. FE-SEM images revealed a spherical particle. HR- TEM also revealed the spherical shape with grain sizes ranging from 48 to 55 nm. The sample exhibited super paramagnetic behaviour as the saturation magnetization value increased due to an increase in the x-value of ferrite. Similarly, with an increase in frequency, the loss in dielectric properties of the samples was observed due to the change in the electrical conduction in the ferrites