The present invention relates to a sealing device and an associated flight control surface mechanism and an associated aircraft. According to an aspect of the present invention, a sealing device (100, 100') for a flight control surface mechanism (10) of an aircraft (1) is provided, the flight control surface mechanism includes a fixed part (20) and a movable wing surface (40), the movable wing surface is attached to the fixed part in a manner of being movable relative to the fixed part. The sealing device includes a fixed seal (120) attached to the fixed part and a movable seal (140, 140') attached to the movable wing surface so as to move with the movement of the movable wing surface, the movable seal and the fixed seal cooperate with each other in order to provide an aerodynamic sealing for the flight control surface mechanism. According to the present invention, a good aerodynamic sealing of the flight control surface mechanism can be effectively maintained, and the efficiency of the movable wing surface and thus the aerodynamic performance of the flight control surface mechanism can be effectively ensured.