All the compositions in the (1−x)Mg_0.95Ni_0.05Ti_0.98Zr_0.02O₃–xCa_0.6La_0.8/3TiO₃ (0 ≤ x ≤ 0.2) series were fabricated using solid state sintering route. Mg_0.95Ni_0.05Ti_0.98Zr_0.02O₃ possessed excellent microwave dielectric properties with ${\epsilon }_{\text{r}}$ ≈ 17.1, $Q_{\text{u}}{f}_{\text{0}}$ ≈ 195855 GHz, and ${\tau }_f$ ≈ -46 ppm/℃. ${\tau }_f$ was tuned through zero by mixing with Ca_0.6La_0.8/3TiO₃. In the present study, ${\tau }_f$ ≈ -2 ppm/℃ with ${\epsilon }_{\text{r}}$ ≈ 23.9 and high $Q_{\text{u}}{f}_{\text{0}}$ ≈ 115870 GHz was achieved for x = 0.15, i.e., for a mixture of 85% Mg_0.95Ni_0.05Ti_0.98Zr_0.02O₃ and 15% Ca_0.6La_0.8/3TiO₃.