This paper proposes an optimal backstepping control-based bat algorithm (BA-OBC) scheme for the attitude of unmanned aerial vehicle with disturbance observer. The proposed controller offers an interesting designed strategy allowing the state trajectory to track a desired trajectory with disturbance observer combined with backstepping controller in order to guarantee the robustness of the proposed approach to integrate the Bat algorithm to ensure the optimal parameters of the proposed method. The global stability analysis is proved via Lyapunov theory. The results of numerical simulations on the quadrotor helicopter system demonstrate the robustness and the effectiveness of the proposed control strategy.