An orthosis for the correction of a varus/valgus malalignment of a person comprises a support device which in the frontal plane has an L shape and a support limb (2) reaching under the foot of the person and establishing contact with a tread (4) and a splint arrangement (7) extending laterally upwards along the leg, said splint arrangement being connectible to the lower leg of the person via a fastening device (13). A bracket which is rigid when under stress is provided at the transition from the support limb (2) to the splint arrangement (7). The splint arrangement (7) is subdivided into a contact limb (3) to rest laterally against the foot and a splint (6) to rest laterally against the lower leg and to exert a torque onto the lower leg by a rotary joint (5) which is arranged approximately at the level of the ankle joint. The orthosis according to the invention allows an effective correction of the malalignment using only one foot part (1) and a splint (6) which extends laterally along the lower leg. For this purpose, the splint (6) is designed as a resilient element and the torque is the result of a preset bias of the resilient element relative to the lower leg.