A safety stirrup for horseback riding having a first semi-arch element having a first end integrally connected to a first portion of a base element of the stirrup and a second end comprising a through hole (4) for mounting a stirrup leather; a second semi-arch element having an end elastically connected to a second portion of the base element opposed to the first portion is provided. The second semi-arch element is configured to delimit a portion for inserting a rider's foot into the stirrup. The stirrup comprises a support platform for the rider's foot associated with the base element. The platform is removably attached to the base element and the stirrup and may have elastic interposed between the platform and the base element, configured to define a distance between the platform and the base element in an initial rest condition, and adjustment means acting on the elastic means for changing the first distance from the initial rest condition.