Abstract— <p>This investigation focused on the impact of ZrO₂ doping on phase formation, microstructure, sintering kinetics, and electrical properties of ZnO-based ceramic varistors, with ZrO₂ content ranging from 0.0 to 1.0 mol&#xa0;%. The varistors enriched with various amounts of ZrO₂ were prepared via a conventional solid-state reaction route and sintered at 1200°C for 2 h. Microstructural analysis was conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The capacity of ZrO₂ to enhance the sintering process is well demonstrated through thermal analysis kinetics by determining the Arrhenius parameters. Electrical properties and current–voltage (<i>I–V</i>) characteristics were assessed using a DC parameter instrument. The results reveal that ZrO₂ doping inhibits ZnO grain growth by anchoring grain boundaries and promotes the formation of the spinel phase (Zn₄Ni₃Sb₂O₁₂)_0.333. ZrO₂ addition effectively improves the sintering process. The activation energy of ZnO varistors, which are doped with ZrO₂, is significantly lower compared to undoped varistors. Doping with ZrO₂ enhances the nonlinear exponent (α) of the varistors up to 0.25&#xa0;mol&#xa0;%, leading to increased varistor voltage and reduced leakage current. For instance, at 0.25 mol&#xa0;% ZrO₂, the nonlinear exponent (α) reaches a peak of 41, with a varistor voltage of approximately 320 V&#xa0;mm^–1. Conversely, varistors containing 1.0 mol&#xa0;% ZrO₂ exhibit a lower voltage (210 V&#xa0;mm^–1) and α below 25. The findings suggest that the proposed varistor composition and processing method are promising for low-voltage power transmission systems.</p>