This study presents the characterization and optimization of BaTiO<sub>3</sub>-doped ZnO-based varistors for electrical and electronic applications. The varistors were prepared using a conventional ceramic procedure and were sintered at a temperature of 1,000 °C with different concentrations of BaTiO<sub>3</sub> (0 and 3 mol%) added to the Bi<sub>2</sub>O<sub>3</sub>/ZnO-based varistor composition (99.5 mol% ZnO and 0.5 mol% Bi<sub>2</sub>O<sub>3</sub>). The results showed that the addition of BaTiO<sub>3</sub> led to the formation of various oxides and solid solutions, such as Bi1<sub>2</sub>TiO<sub>20</sub>, BaTiO<sub>3</sub>, and (Bi<sub>2</sub>O<sub>3</sub>)<sub>0.80</sub> (BaO)<sub>0.20</sub>. The dielectric constant and grain size decreased with increasing BaTiO<sub>3</sub> content, while the non-linearity coefficient, electric fields (Eb) increased, and dielectric loss (Tanδ) decreased. The optimized varistor contains 2 mol% BaTiO<sub>3</sub> and an electric field of 148.08 V/mm, which are superior to those of the BaTiO<sub>3</sub>/Bi<sub>2</sub>O<sub>3</sub>/ZnO-based varistor. During this study, we were able to observe that a slight addition of BaTiO<sub>3</sub> will increase the breakdown voltage and the coefficient of nonlinearity and this will allow us to develop low-dimensional varistors and install them in the high-voltage domain.