The present invention provides high-lift devices, wings, and noise reduction structures for the high-lift devices capable of suppressing the occurrence of aerodynamic noise while restricting an increase in airframe weight. A high-lift device includes: a slat main body (4) that is disposed so as to be able to extend from and retract into a main wing; a concave part (5) that is formed on the slat main body (4) at a location that faces the main wing, so as to be able to accommodate at least a part of a leading edge of the main wing; and an airflow control part (6) that is disposed at an area in the concave part (5) facing an upper surface of the main wing, that is accommodated between the main wing and the concave part when the slat main body (4) is retracted into the main wing, and that suppresses turbulence colliding against the area in the concave part (5) facing the upper surface of the main wing when the slat main body (4) is extended from the main wing.