A process for applying noise-reducing elements to a tyre for vehicle wheels. A plurality of noise-reducing elements are arranged on a feeding belt movable along a predetermined feeding direction. The noise-reducing elements are subsequently aligned along the feeding direction and brought into mutual contact, to then be transferred onto a service plane arranged downstream of the feeding belt along the feeding direction and having, on an upper surface thereof, a continuous film which supports a layer of adhesive material. The layer of adhesive material is applied onto a lower surface of each of the noise-reducing elements taking it from the continuous film. The noise-reducing elements are then transferred one by one onto a conveyor belt arranged downstream of the service plane along the feeding direction. The noise-reducing elements are finally positioned one by one on a radially inner surface of a tyre.