An aircraft wing including a mobile leading edge flap associated with a guiding device arranged at the front of a front spar of a wing box, and including: —a pivoting member having one end connected to the spar by an articulated linkage; —a pivoting member connected to one end of the member by an articulated linkage, the end of this member being connected to the flap via an articulated linkage; —a guide rail receiving a tracking member supported by the member, the rail defining a path inscribed on the surface of an imaginary sphere, the centre of which corresponds to a point of convergence of the axes of the three linkages.