Nano-ferrite MgMoxFe2-xO4 (x= 0.0, 0.05, 0.15, and 0.3)were synthesized employing citrate sol-gel auto combustion methodology. X-ray diffraction (XRD) reveals the crystal structure of the prepared samples., XRD scrutiny disclosed a single cubic spinel phase for all specimens. Furthermore, the Rietveld analysis based on structure refinement used to determine the microstructural parameters and evaluate the cation distribution. The findings showed that the average crystallite size was ~39 nm, while the lattice constant “a” increases with increasing Mo concentrations attributable to introducing Mo+6 to supplant Fe+3. The magnetic properties were investigated utilizing VSM magnetometer. The saturation magnetization (Ms) descends with escalating Mo+6 replacement. Consequently, both Rietveld scrutiny and saturation magnetization (Ms) results suggest that the Mo+6 supplanted Fe+3 in octahedral B-locations. On the other hand, reflectance and transmittance were used in optical properties to calculate the refractive index, n, and the extinction coefficient, k. The parameters of optical properties such as infinity, lattice and relaxation time of dielectric constant were estimated. In addition, complex optical conductivity, optical electronegativity and optical transitions of all studied samples were assessed. Finally, the parameters of opto-electrical application, such as the concentration, mobility and resistivity of optical carrier were appraised.