<p>This article reports In₂O₃ thin-film transistors (TFTs) that utilize a CeAlO_<i>x</i>/Al₂O₃ stacked gate dielectric architecture. The CeAlO_<i>x</i> gate dielectric films were optimized by doping Al into CeO₂, where the adjustment of the Al/Ce atomic ratio effectively suppressed oxygen-vacancy-related defects and optimized gate dielectric leakage current. Due to the large bandgap and high density of Al₂O₃ prepared via atomic layer deposition (ALD), CeAlO_<i>x</i>/Al₂O₃ stacked gate dielectric exhibits lower leakage current compared to single-layer CeAlO_<i>x</i>. We systematically investigated the Al/Ce ratio’s dependence on In₂O₃ TFT performance, identifying an optimal stoichiometry of 3:7 (Al:Ce). The CeAlO_<i>x</i>/Al₂O₃-based In₂O₃ TFT fabricated at this ratio achieved exceptional characteristics: higher saturation mobility (26.86 cm² V⁻¹ s⁻¹) and on/off current ratio (3.58 × 10⁷), lower subthreshold swing (0.08 V decade⁻¹) and interface state density (1.39 × 10¹² cm⁻²), coupled with excellent bias stress stability. By combining low-frequency noise analysis and X-ray photoelectron spectroscopy (XPS), we confirmed that Al doping reduces the trap density in CeO₂ while simultaneously enhancing its dielectric properties. Furthermore, a resistive-load inverter based on In₂O₃ TFT presents a voltage gain up to 15.1 at an applied voltage of 5 V with a typical reverse behavior, demonstrating that In₂O₃ TFT based on CeAlO_<i>x</i>/Al₂O₃ stacked gate dielectric exhibits potential for application in advanced digital circuits.</p> Graphical abstract <p></p>