<p>Lead-free BaZrₓTi_1-xO₃ (BZT) thin films with varying Zr content (0.0 ≤ x ≤ 0.35) were synthesized via a sol–gel method. The effects of Zr content on the structure, diffuse phase transition, dielectric and ferroelectric properties, temperature coefficients of capacitance, and leakage current of the films were investigated. It was discovered that Zr doping introduces significant B-site disorder, which is manifested as a disruption of long-range ferroelectric order, a reduction in tetragonal distortion, and grain refinement. These structural changes are directly accountable for a lowered and broadened phase transition, the development of relaxor-like characteristics, and a remarkable suppression of leakage current due to the stabilized Ti⁴⁺ valence state. Zr doping led to a significant improvement in dielectric and ferroelectric properties at room temperature and reduced the leakage current. At the composition of x = 0.2, the BZT thin film demonstrates optimal dielectric properties. It has a moderate dielectric constant of 1252, a low dielectric loss of 0.053, and the temperature coefficient of capacitance (TCC) is maintained within ± 15% over a broad temperature range from –55&#xa0;°C to 200&#xa0;°C, meeting the X9R capacitor specification. This could be promising for practical applications in electronic devices with wider operating temperatures.</p>