To investigate the clinical and radiographic results of anterior tibial tendon (ATT) transfer combined with supramalleolar osteotomy in stage 3b of varus ankle osteoarthritis. Totally 13 patients with stage 3b of varus ankle osteoarthritis who received ATT transfer combined with supramalleolar osteotomy in Beijing Tongren Hospital from January 2018 to May 2021 were recruited. There were 6 males and 7 females with a mean age of (57.8±9.3) years. The overall evaluations included the preoperatively and postoperatively radiographic alignments, visual analog scale (VAS) score, and the American Orthopaedic Foot & Ankle Society (AOFAS) clinical ankle-hindfoot scale. The mean follow-up period was (33.5±13.4) months. The tibial articular surface (TAS), talar tilt (TT), and foot and ankle offset (FAO) changed from 83.3°±2.4° to 92.8°±1.7°, 12.3°±4.5° to 7.0°±4.7°, and -7.4%±2.8% to -0.7%±2.2% after the operation, respectively (all <0.001). The AOFAS and VAS score improved significantly at the final follow-up when compared with those before the operation (both <0.001). It indicated that ATT transfer after supramalleolar osteotomy can achieve good clinical and radiographic results in the treatment of varus ankle arthritis in Takakura stage 3b.