<p>Spinel ferrites of nickel ferrite (NiFeO₄) and nickel manganite (NiMnO₄) were synthesized using a WOW sol–gel technique, and their structural and electrical properties were examined. XRD confirmed cubic spinel structures with crystallite sizes ranging from 29 to 66 nm and lattice constants between 8.31 and 8.40 Å. The porosity values were 41–44%, and the experimental densities calculated from XRD data ranged from 2.89 to 3.15 g/cm³. The dielectric constants were determined to be 19.4 for NiFeO₄, 32.1 for NiMnO₄, 5.9 for NiFeO₄/CNTs, and 17.7 for NiMnO₄/CNTs at high frequencies up to 1 MHz, showing a significant reduction compared to their low-frequency values. Dielectric losses also decreased at higher frequencies, ranging from 1.2 to 12.7 across all compositions. With increasing frequency, the AC conductivity reached ~ 6.7 × 10⁻⁵ S/cm for NiFe₂O₄ and ~ 7.0 × 10⁻⁴ S/cm for NiMn₂O₄ at 1 MHz. DC electrical measurements revealed semiconducting behavior, with activation energies of 0.68 eV for NiFeO₄, 0.56 eV for NiFeO₄/CNTs, 0.43 eV for NiMnO₄, and 0.35 eV for NiMnO₄/CNTs. Impedance analysis confirmed an increase in resistance for NiFeO₄/CNTs and a decrease in resistance for NiMnO₄/CNTs. These findings show that the addition of CNTs dramatically alters the dielectric and transport characteristics, especially at high frequencies, allowing ferrites to be precisely tailored for high-frequency electrical and energy storage applications.</p>