<p>This study presents a detailed investigation of the structural, optical, and dielectric properties of Co_0.4Ni_0.3Zn_0.3Fe₂O₄ spinel ferrite prepared using the sol-gel method. The structural analysis of the ferrite was performed using X-ray diffraction, which allowed for the estimation of various parameters including lattice parameter, crystallite size, density, bond lengths, and bond distances. These values were compared with theoretical values to assess the accuracy of the cation distribution. The optical properties of the ferrite were characterized through absorbance measurements, revealing a direct optical transition. The band-gap (<i>E</i>_g) was estimated to be 2.15 eV, while the Urbach (<i>E</i>_u) energy was found to be 4.76 eV. These results indicate the material’s potential for light-absorbing and light-emitting applications, making it suitable for use in solar cells and optoelectronic devices. Furthermore, the examination of electrical conductivity data demonstrated the semiconductor behavior of the prepared ferrite, following the NSPT model for conduction. The activation energy (<i>E</i>_<i>a</i>) was found to be 0.22 eV. The Ghosh scaling analysis revealed a remarkable convergence of the conductivity isotherms, forming a nearly unified master curve. The sample exhibited an elevated electrical resistivity of approximately 10⁹ Ω.m near room temperature, emphasizing its potential suitability for utilization in electronic applications, such as microwave devices.</p> Graphical Abstract <p></p>