Herein, lanthanum doping effects on the structural, dielectric, and electrical properties of Ba1−xLax(Zn1/3Nb2/3)O3 (BZN) solid solutions are focused upon. The La contents which are varied in the range of 0.02–0.20 exhibit a solubility limit of x = 0.02. Although minor phases of Ba5Nb4O15 and Ba3LaNb3O12 appear for samples doped with La contents of x = 0.05 and x = 0.10, they play no remarkable role for the enhanced structural and dielectric properties of BZN. The La doping content of x = 0.02 succeeds in increasing the crystallite size by 51.16% and lowering the microstrain by 34.18% and defect concentration by 63.10%. La‐doped BZN ceramics display higher values of relative density and electrical conductivity. The analyses of the dielectric spectra as a function of temperature display dielectric relaxation behavior above 120 °C. In the temperature range of 20–120 °C, La doping changes the temperature coefficient of dielectric constants from +30 ppm °C−1 in pure samples to −341 ppm °C−1 in samples doped with La contents of x = 0.10. The enhancements in structural parameters, density values, and dielectric responses that are achieved via La doping make BZN ceramics more suitable for electronic device fabrication.