This article proposes a versatile controller based on the incremental strategy to explore a finite‐time (FT) solution of fixed‐wing unmanned aerial vehicle (UAV) maneuver control considering the lumped disturbances such as unmodeled dynamics or exogenous perturbations. First, a finite‐time nonlinear disturbance observer augmented with a neural network item is developed to attenuate the adverse effect of the disturbances mentioned above. Then considering the estimated lumped disturbance, a finite‐time incremental controller in the quaternion form is proposed. Rigorous proof shows that the nonlinear disturbance observer and controller achieve finite‐time convergence. In the numerical simulation, the superiority of the proposed method compared to several advanced nonlinear control approaches is illustrated, despite the mismatches in aerodynamic coefficients, wind gusts, and actuator failures. Furthermore, based on a novel model identification approach, a hardware‐in‐the‐loop (HITL) experiment is performed in a high‐fidelity environment, wherein our method's feasibility and practicability are verified.