<p>In this paper, a novel control strategy for the attitude stabilization of a nonlinear aircraft model is proposed, integrating active disturbance rejection control (ADRC) with the smart super-twisting sliding mode control (ST-SMC) algorithm. The primary objective of this study is to enhance the control system’s robustness against disturbances while improving tracking accuracy. The proposed method leverages a nonlinear extended state observer (NESO) to accurately estimate the lumped disturbances and system uncertainties. These estimated disturbances are actively compensated within the control law, thereby transforming the uncertain nonlinear system into a simplified compensated system. To ensure robust tracking and effective disturbance rejection, a high-order sliding mode control law based on the super-twisting algorithm is implemented, where the gains of the super-twisting controller are tuned using the reinforcement learning (RL) method. The stability of the nonlinear extended state observer and the super-twisting ADRC is theoretically analyzed, and closed-loop stability is proved. Extensive simulations are conducted on a nonlinear aircraft model under various disturbance scenarios, including actuator faults, aerodynamic uncertainties, and atmospheric disturbances. The results demonstrate the superiority of the proposed method over traditional control strategies, such as Linear ADRC and classical ST-SMC, in terms of convergence speed, robustness, and disturbance rejection performance. This study contributes significantly to flight control systems, offering a robust and efficient solution for modern aerospace applications.</p>