The posture-enforcing seat is a chair. The posture-enforcing seat is a therapeutic structure. The posture-enforcing seat is adapted for use with a patient. The posture-enforcing seat forms a physical boundary that limits the lateral motion of the thighs of the patient. The posture-enforcing seat comprises a chair structure and a plurality of corrective structures. The plurality of corrective structures attach to the chair structure. The plurality of corrective structures forms the boundary structure that limits the lateral motion of the thighs of the patient.