Past studies of the relation between teacher-student relationship (TSR) and students' academic achievement (SAA) yielded mixed results, so this study determined the overall link between TSR and SAA, along with their moderators. This three-level meta-analysis of 90 independent effect sizes in 74 empirical studies of 233,961 students showed an overall positive link between TSR and SAA in China (r = 0.259, 95% CI = [0.227; 0.290]). This relationship was higher in: (a) China's central region (0.305) than its eastern (0.238) or western regions (0.166); (b) senior high school (0.345), followed by junior high school (0.251), then primary school (0.221); (c) English (0.302), followed by math (0.272), Chinese (0.269), and science (0.202); and (d) females (B = 0.507) than males. These results suggest the value of improving teacher-student relationships in policies and practices.