Background: Anterior open bite involving the anterior dentition associated with skeletal Class III malocclusion is a severe dentofacial deformity resulting from discrepancies in vertical and sagittal relationships of the maxilla and mandible. In adult patients, orthodontic treatment alone is insufficient to achieve satisfactory outcomes; therefore, combined orthodontic and orthognathic surgical treatment is required. Case Presentation: A 21-year-9-month-old female patient presented with a chief complaint of mandibular prognathism. Clinical and radiographic examinations revealed anterior open bite involving the anterior dentition associated with skeletal Class III malocclusion. The treatment was carried out in three phases. Presurgical orthodontic treatment was performed to achieve dental decompensation, followed by orthognathic surgery. Le Fort I osteotomy was performed to reduce the vertical height by 3 mm and advance the maxilla by 5 mm, while bilateral sagittal split osteotomy (BSSO) was performed to set back the mandible by 9 mm. Post-surgical orthodontic treatment was performed using temporary anchorage devices (TADs) to provide stable anchorage, allowing precise control of tooth movement, and intermaxillary elastics were used to refine occlusion. As a result, facial profile, skeletal relationships, and occlusion were improved, with stable outcomes achieved. Diagnosis: Extraoral examination revealed a mandibular facial profile, increased height of the lower third of the face, normal facial midline at the nose, and a 1.5 mm leftward deviation at the chin. Lip position was -6 mm for the upper lip and -2 mm for the lower lip relative to the nasolabial angle. The angle between the cheekbones and the lips was 55.5°. Conclusion Combined orthodontic and orthognathic surgical treatment provides effective and stable outcomes in terms of esthetics, function, and occlusal stability in adult patients with anterior open bite associated with skeletal Class III malocclusion.